How to recover from a corrupted registry that prevents Windows XP from starting

How to run system restore manually:
Solution: Click Here

How to recover from a corrupted registry that prevents Windows XP from starting

How to run system restore manually:
Solution: Click Here

pictures

pictures

You receive the "The operation failed. An object could not be found" error message when you click Send and Receive in Outlook

Solution:

To resolve this behavior, create a new profile. To do this, follow these steps:

1. Click Start, point to Settings, and then click Control Panel.
2. Double-click the Mail icon.
3. In the Mail Setup dialog box, click Show Profiles.
   
   If you want to be able to select a specific profile each time you start Outlook, click the General tab, click Prompt for a profile to be used, and then click Add.
4. In the New Profile dialog box, under Profile Name, type a descriptive name for the new profile, and then click OK.
5. In the E-mail Accounts dialog box, select Add a new e-mail account in the e-mail options, and then click Next.
6. Click the type of server that your e-mail account works with, and then click Next.
7. Complete all of the required fields, including those that are on the tabs that appear after you click More Settings.
8. When you finish providing the required information, click Finish.

You receive the "The operation failed. An object could not be found" error message when you click Send and Receive in Outlook

Solution:

To resolve this behavior, create a new profile. To do this, follow these steps:

1. Click Start, point to Settings, and then click Control Panel.
2. Double-click the Mail icon.
3. In the Mail Setup dialog box, click Show Profiles.
   
   If you want to be able to select a specific profile each time you start Outlook, click the General tab, click Prompt for a profile to be used, and then click Add.
4. In the New Profile dialog box, under Profile Name, type a descriptive name for the new profile, and then click OK.
5. In the E-mail Accounts dialog box, select Add a new e-mail account in the e-mail options, and then click Next.
6. Click the type of server that your e-mail account works with, and then click Next.
7. Complete all of the required fields, including those that are on the tabs that appear after you click More Settings.
8. When you finish providing the required information, click Finish.

Unable to view PDF file in browser

Note: You need to take registry back up to modify anything in registry.

How to back up and restore the registry in Windows

SUMMARY

When you view a PDF file in a browser (for example, Internet Explorer or Firefox), the following error message occurs, 'The Adobe Acrobat/Reader that is running cannot be used to view PDF files in a web browser. Adobe Acrobat/Reader version 8 or 9 is required. Please exit and try again.'

Step 1

1. Go to Start > Run
2. Type regedit and click OK.
3. Browse to the following key: HKEY_CLASSES_ROOT\Software\Adobe\Acrobat\Exe Make sure that the correct Default data value is set for the path where Adobe Reader or Acrobat are installed.
   
   Note : The default installation values are 'C:\Program Files\Adobe\Reader 9.0\Reader\AcroRd32.exe' or 'C:\Program Files\Adobe\Reader 9.0\Reader\Acrobat.exe', depending on whether Adobe Reader or Adobe Acrobat is installed

Step 2

To configure Acrobat or Adobe Reader as a helper application:

1. Start Acrobat or Adobe Reader.
2. Choose Edit > Preferences.
3. Select Internet on the left. Deselect Display PDF In Browser Using [Acrobat application], and then click OK.
4. Quit Acrobat or Adobe Reader.

Unable to view PDF file in browser

Note: You need to take registry back up to modify anything in registry.

How to back up and restore the registry in Windows

SUMMARY

When you view a PDF file in a browser (for example, Internet Explorer or Firefox), the following error message occurs, 'The Adobe Acrobat/Reader that is running cannot be used to view PDF files in a web browser. Adobe Acrobat/Reader version 8 or 9 is required. Please exit and try again.'

Step 1

1. Go to Start > Run
2. Type regedit and click OK.
3. Browse to the following key: HKEY_CLASSES_ROOT\Software\Adobe\Acrobat\Exe Make sure that the correct Default data value is set for the path where Adobe Reader or Acrobat are installed.
   
   Note : The default installation values are 'C:\Program Files\Adobe\Reader 9.0\Reader\AcroRd32.exe' or 'C:\Program Files\Adobe\Reader 9.0\Reader\Acrobat.exe', depending on whether Adobe Reader or Adobe Acrobat is installed

Step 2

To configure Acrobat or Adobe Reader as a helper application:

1. Start Acrobat or Adobe Reader.
2. Choose Edit > Preferences.
3. Select Internet on the left. Deselect Display PDF In Browser Using [Acrobat application], and then click OK.
4. Quit Acrobat or Adobe Reader.

PDF file doesn't open in web browser (Acrobat 6.0, Adobe Reader 6.0 on Windows)

Error : 'The Adobe Acrobat/Reader that is running cannot be used to view PDF files in a web browser. Adobe Acrobat/Reader version 8 or 9 is required. Please exit and try again.'

Issue

When you try open an Adobe PDF file in a Web browser, a blank screen appears.

Detail

The PDF file is hosted on a Web Server that uses Netegrity SiteMinder for security.

Solutions

Do one of the following:

Solution 1: Update to AdobeAcrobat 6.0.1 or Adobe Reader6.0.1.

-- To update to Acrobat 6.0.1:

1. Start Acrobat 6.0.

2. Choose Help > Update.

3. Follow the on-screen instructions to install the update.

Note: You can also download the update from the Adobe Web site at www.adobe.com/support/downloads/main.html .

-- To update to Adobe Reader 6.0.1, download the update from the Adobe Web site at www.adobe.com/products/acrobat/readstep2.html

Solution 2: Save the PDF file to your hard drive, and open it in Acrobat or Adobe Reader.

1. Right-click the link to the PDF file on the Web site, and then choose Save Target As (Internet Explorer) or Save Link As (Netscape Navigator).

2. In the Save As dialog box, select a location on the hard disk, and then click Save.

3. Double-click the PDF file to open it in Acrobat or Adobe Reader.

Solution 3: Disable Web Browser Integration.

1. In Acrobat or Adobe Reader, choose Edit > Preferences > Internet.

2. Deselect Display PDF in Browser, and then click OK.

Backgroundinformation

Because of the large file headers produced by SiteMinder, Acrobat 6.0 and Adobe Reader 6.0 cannot display PDF files in a browser if the PDF files are hosted on a Web server that uses SiteMinder.

Additional Information

325875 PDF pages don't appear in web browser window (Acrobat 4.0-6.0.x, Adobe Reader 4.0-6.0x)*

PDF file doesn't open in web browser (Acrobat 6.0, Adobe Reader 6.0 on Windows)

Error : 'The Adobe Acrobat/Reader that is running cannot be used to view PDF files in a web browser. Adobe Acrobat/Reader version 8 or 9 is required. Please exit and try again.'

Issue

When you try open an Adobe PDF file in a Web browser, a blank screen appears.

Detail

The PDF file is hosted on a Web Server that uses Netegrity SiteMinder for security.

Solutions

Do one of the following:

Solution 1: Update to AdobeAcrobat 6.0.1 or Adobe Reader6.0.1.

-- To update to Acrobat 6.0.1:

1. Start Acrobat 6.0.

2. Choose Help > Update.

3. Follow the on-screen instructions to install the update.

Note: You can also download the update from the Adobe Web site at www.adobe.com/support/downloads/main.html .

-- To update to Adobe Reader 6.0.1, download the update from the Adobe Web site at www.adobe.com/products/acrobat/readstep2.html

Solution 2: Save the PDF file to your hard drive, and open it in Acrobat or Adobe Reader.

1. Right-click the link to the PDF file on the Web site, and then choose Save Target As (Internet Explorer) or Save Link As (Netscape Navigator).

2. In the Save As dialog box, select a location on the hard disk, and then click Save.

3. Double-click the PDF file to open it in Acrobat or Adobe Reader.

Solution 3: Disable Web Browser Integration.

1. In Acrobat or Adobe Reader, choose Edit > Preferences > Internet.

2. Deselect Display PDF in Browser, and then click OK.

Backgroundinformation

Because of the large file headers produced by SiteMinder, Acrobat 6.0 and Adobe Reader 6.0 cannot display PDF files in a browser if the PDF files are hosted on a Web server that uses SiteMinder.

Additional Information

325875 PDF pages don't appear in web browser window (Acrobat 4.0-6.0.x, Adobe Reader 4.0-6.0x)*

How to Install IIS on Windows Vista

If you are a developer using ASP.NET, one of the first things you'll want to install on Vista is IIS (internet information server). Keep in mind that your version of Vista may not come with IIS. I'm using Vista Ultimate edition.

First, go to Control Panel, and then click on Programs. You'll see a link for "Turn Windows features on or off"

If you expand the Internet Information Services tree node, you can see that there are a lot of options beneath it. You will probably want to explore these options, because even if you click on IIS, some of the necessary options for doing development aren't checked.

Once you've gone ahead and checked the items you want, and clicked OK, you'll see this dialog for a while….

Now when you navigate in your browser to localhost, you'll see the new default page… slick!

How to Install IIS on Windows Vista

If you are a developer using ASP.NET, one of the first things you'll want to install on Vista is IIS (internet information server). Keep in mind that your version of Vista may not come with IIS. I'm using Vista Ultimate edition.

First, go to Control Panel, and then click on Programs. You'll see a link for "Turn Windows features on or off"

If you expand the Internet Information Services tree node, you can see that there are a lot of options beneath it. You will probably want to explore these options, because even if you click on IIS, some of the necessary options for doing development aren't checked.

Once you've gone ahead and checked the items you want, and clicked OK, you'll see this dialog for a while….

Now when you navigate in your browser to localhost, you'll see the new default page… slick!

Error while running ipconfig /flushdns command : "Could not flush the DNS Resolver Cache: Function failed during execution."

When you run the ipconfig /flushdns command to clear the Domain Name System (DNS) cache on a Microsoft Windows XP-based computer, you receive an error message that resembles the following:

Could not flush the DNS Resolver Cache: Function failed during execution.

When you try to repair the network connection, you receive an error message that resembles the following:

Windows could not finish repairing the problem because the following action could not be completed:
Clearing the DNS Cache

For assistance, contact the person who manages your network.

Cause: This problem occurs if the DNS Client service is not running on the computer.

To resolve this problem, follow these steps:

• Click Start, click Run, type services.msc, and then click OK.

• In the list of services, click DNS Client.

• Make sure that the Status column displays Started and that the Startup Type column displays Automatic.

• If the service is not set to Started or if the startup type for the DNS Client service is not set to Automatic, follow these steps:

• Right-click DNS Client, and then click Properties.

• In the DNS Client Properties dialog box, click the General tab, and then click Automatic in the Startup type list.

• Click Start, click Apply, and then click OK.

Error while running ipconfig /flushdns command : "Could not flush the DNS Resolver Cache: Function failed during execution."

When you run the ipconfig /flushdns command to clear the Domain Name System (DNS) cache on a Microsoft Windows XP-based computer, you receive an error message that resembles the following:

Could not flush the DNS Resolver Cache: Function failed during execution.

When you try to repair the network connection, you receive an error message that resembles the following:

Windows could not finish repairing the problem because the following action could not be completed:
Clearing the DNS Cache

For assistance, contact the person who manages your network.

Cause: This problem occurs if the DNS Client service is not running on the computer.

To resolve this problem, follow these steps:

• Click Start, click Run, type services.msc, and then click OK.

• In the list of services, click DNS Client.

• Make sure that the Status column displays Started and that the Startup Type column displays Automatic.

• If the service is not set to Started or if the startup type for the DNS Client service is not set to Automatic, follow these steps:

• Right-click DNS Client, and then click Properties.

• In the DNS Client Properties dialog box, click the General tab, and then click Automatic in the Startup type list.

• Click Start, click Apply, and then click OK.

ERROR MESSAGE: “DATA EXECUTION PREVENTION”

If you click Close Message, the program quits, and Windows Error Reporting gives you the option to send an error report.

Causes:

There can be many like:-

• Due to some issues in a program/software e.g. drivers, applications, etc.

• If you have used a crack against Windows OS executables, DLL files, etc.

• Some malicious software might have harmed your system files or changed the security settings.

What is Data Execution Prevention?

Data Execution Prevention (DEP) is a security feature that can help prevent damage to your computer from viruses and other security threats. Harmful programs can try to attack Windows by attempting to run (also known as execute) code from system memory locations reserved for Windows and other authorized programs. These types of attacks can harm your programs and files.

DEP was introduced in Windows XP Service Pack 2 and is included in Windows XP Tablet PC Edition 2005, Windows Server 2003 Service Pack 1 and later, Windows Vista, and Windows Server 2008. It is also included in beta versions of Windows 7.

DEP can help protect your computer by monitoring your programs to make sure that they use system memory safely. If DEP notices a program on your computer using memory incorrectly, it closes the program and notifies you.

It's a feature that can be turned on or off, or be configured.

Turning Off DEP

You can turn off DEP completely by doing this:-

• Right click on My Computer

• Click on Properties

• Click on the Advanced tab

• Click on the Settings button in the Performance section

• Click on the Data Execution Prevention tab and make necessary settings.

Alternatively you can also do the following:-

1. Click Start, click Run, type sysdm.cpl, and then click OK.

2. On the Advanced tab, under Performance, click Settings.

3. On the Data Execution Prevention tab, use one of the following procedures:

   • Click Turn on DEP for essential Windows programs and services only to select the OptIn policy.

   • Click Turn on DEP for all programs and services except those I select to select the OptOut policy, and then click Add to add the programs that you do not want to use the DEP feature.

4. Click OK two times.

Configure Exceptions to DEP

If you have a program you know is genuine and that happens to cause DEP errors you can add it to the list of exceptions.

To do so, click on the Add button. And locate the software or program's ".exe" file. Let’s take “Foxit PDF reader” as an example.

In this example the program is located in "C:\Program Files\Foxit Software\Foxit Reader\Foxit Reader.exe". The final result should look something like this:

Now, the program has been added to the list of exceptions. It will not be protected by DEP, but everything else in your system will be.

However, if you get the following message while turning off the DEP for a program:-

"This program must run with data execution prevention (DEP) enabled.
You cannot turn off DEP for this program."

Then the most likely reason can be that the program is cracked or it’s not in its original form. In such a situation reinstall or replace that program with its original version. And then you can turn off the DEP for the same.

Note: In general scenario it is suggested NOT to turn off the DEP.

ERROR MESSAGE: “DATA EXECUTION PREVENTION”

If you click Close Message, the program quits, and Windows Error Reporting gives you the option to send an error report.

Causes:

There can be many like:-

• Due to some issues in a program/software e.g. drivers, applications, etc.

• If you have used a crack against Windows OS executables, DLL files, etc.

• Some malicious software might have harmed your system files or changed the security settings.

What is Data Execution Prevention?

Data Execution Prevention (DEP) is a security feature that can help prevent damage to your computer from viruses and other security threats. Harmful programs can try to attack Windows by attempting to run (also known as execute) code from system memory locations reserved for Windows and other authorized programs. These types of attacks can harm your programs and files.

DEP was introduced in Windows XP Service Pack 2 and is included in Windows XP Tablet PC Edition 2005, Windows Server 2003 Service Pack 1 and later, Windows Vista, and Windows Server 2008. It is also included in beta versions of Windows 7.

DEP can help protect your computer by monitoring your programs to make sure that they use system memory safely. If DEP notices a program on your computer using memory incorrectly, it closes the program and notifies you.

It's a feature that can be turned on or off, or be configured.

Turning Off DEP

You can turn off DEP completely by doing this:-

• Right click on My Computer

• Click on Properties

• Click on the Advanced tab

• Click on the Settings button in the Performance section

• Click on the Data Execution Prevention tab and make necessary settings.

Alternatively you can also do the following:-

1. Click Start, click Run, type sysdm.cpl, and then click OK.

2. On the Advanced tab, under Performance, click Settings.

3. On the Data Execution Prevention tab, use one of the following procedures:

   • Click Turn on DEP for essential Windows programs and services only to select the OptIn policy.

   • Click Turn on DEP for all programs and services except those I select to select the OptOut policy, and then click Add to add the programs that you do not want to use the DEP feature.

4. Click OK two times.

Configure Exceptions to DEP

If you have a program you know is genuine and that happens to cause DEP errors you can add it to the list of exceptions.

To do so, click on the Add button. And locate the software or program's ".exe" file. Let’s take “Foxit PDF reader” as an example.

In this example the program is located in "C:\Program Files\Foxit Software\Foxit Reader\Foxit Reader.exe". The final result should look something like this:

Now, the program has been added to the list of exceptions. It will not be protected by DEP, but everything else in your system will be.

However, if you get the following message while turning off the DEP for a program:-

"This program must run with data execution prevention (DEP) enabled.
You cannot turn off DEP for this program."

Then the most likely reason can be that the program is cracked or it’s not in its original form. In such a situation reinstall or replace that program with its original version. And then you can turn off the DEP for the same.

Note: In general scenario it is suggested NOT to turn off the DEP.

ERROR : "Registry Editing has been disabled by your administrator"

Cause: This error occurs if the DisableRegistryTools Policy is enabled (mostly due to an accidental modification or a virus present in your system).

You can perform the steps in any of below methods to remove the registry editing restrictions.

Method 1: Using the REG.EXE console tool

1. Click Start → Run and type this command:

REG add HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System /v DisableRegistryTools /t REG_DWORD /d 0 /f

Now, you should be able to launch the Registry Editor.

Method 2: Using the Group Policy Editor

• Click Start → Run and type gpedit.msc and press ENTER

• Go to the following location:

User Configuration → Administrative Templates → System

• Double-click “Prevent access to registry editing tools”. It will probably be not configured or enabled.

• If it’s enabled, disable it and if it’s not configured, first enable it, apply settings and then disable it.

• Exit the Group Policy Editor

• Run gpupdate in command prompt to apply the group policies.

Note: If the setting already reads Not Configured, set it to Enabled, and click Apply. Then revert it back to Not Configured. This ensures that the DisableRegistryTools registry value is removed successfully.

Method 3 : Copy the following code in a notepad and save it as "reg.vbs". Then double click on it to run it. The registry should be enabled.

'Enable/Disable Registry Editing tools

Option Explicit

'Declare variables
Dim WSHShell, n, MyBox, p, t, mustboot, errnum, vers
Dim enab, disab, jobfunc, itemtype

Set WSHShell = WScript.CreateObject("WScript.Shell")
p = "HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System\"
p = p & "DisableRegistryTools"
itemtype = "REG_DWORD"
mustboot = "Log off and back on, or restart your pc to" & vbCR & "effect the changes"
enab = "ENABLED"
disab = "DISABLED"
jobfunc = "Registry Editing Tools are now "

'This section tries to read the registry key value. If not present an 
'error is generated.  Normal error return should be 0 if value is 
'present
t = "Confirmation"
Err.Clear
On Error Resume Next
n = WSHShell.RegRead (p)
On Error Goto 0
errnum = Err.Number

if errnum <> 0 then
'Create the registry key value for DisableRegistryTools with value 0
        WSHShell.RegWrite p, 0, itemtype
End If

'If the key is present, or was created, it is toggled
'Confirmations can be disabled by commenting out 
'the two MyBox lines below

If n = 0 Then
        n = 1
WSHShell.RegWrite p, n, itemtype
Mybox = MsgBox(jobfunc & disab & vbCR & mustboot, 4096, t)
ElseIf n = 1 then
        n = 0
WSHShell.RegWrite p, n, itemtype
Mybox = MsgBox(jobfunc & enab & vbCR & mustboot, 4096, t)
End If

Method 4 : Heres the script given in italics below. Just copy and paste in a notepad. Name the file as "editregenable.reg". After you get the file just right click and select merege. Then restart the computer:

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System]
"DisableRegistryTools"=dword:00000000

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System]
"**.del.DisableRegistryTools"=-

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Group Policy Objects\LocalUser\Software\Microsoft\Windows\CurrentVersion\Policies\System]
"DisableRegistryTools"=dword:00000000

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Group Policy Objects\LocalUser\Software\Microsoft\Windows\CurrentVersion\Policies\System]
"**del.DisableRegistryTools"=-

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer]
"NoSaveSettings"=dword:00000000

The effects are usually instant, else it works after restarting your computer .

Now try to open the registry editor and see if it works.

Note: If none of the above methods works or your registry editor again gets automatically disabled say after restart, then it is highly likely that there is a virus present in your system. Hence it is recommended that the virus is first removed and then the above steps are performed.

ERROR : "Registry Editing has been disabled by your administrator"

Cause: This error occurs if the DisableRegistryTools Policy is enabled (mostly due to an accidental modification or a virus present in your system).

You can perform the steps in any of below methods to remove the registry editing restrictions.

Method 1: Using the REG.EXE console tool

1. Click Start → Run and type this command:

REG add HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System /v DisableRegistryTools /t REG_DWORD /d 0 /f

Now, you should be able to launch the Registry Editor.

Method 2: Using the Group Policy Editor

• Click Start → Run and type gpedit.msc and press ENTER

• Go to the following location:

User Configuration → Administrative Templates → System

• Double-click “Prevent access to registry editing tools”. It will probably be not configured or enabled.

• If it’s enabled, disable it and if it’s not configured, first enable it, apply settings and then disable it.

• Exit the Group Policy Editor

• Run gpupdate in command prompt to apply the group policies.

Note: If the setting already reads Not Configured, set it to Enabled, and click Apply. Then revert it back to Not Configured. This ensures that the DisableRegistryTools registry value is removed successfully.

Method 3 : Copy the following code in a notepad and save it as "reg.vbs". Then double click on it to run it. The registry should be enabled.

'Enable/Disable Registry Editing tools

Option Explicit

'Declare variables
Dim WSHShell, n, MyBox, p, t, mustboot, errnum, vers
Dim enab, disab, jobfunc, itemtype

Set WSHShell = WScript.CreateObject("WScript.Shell")
p = "HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System\"
p = p & "DisableRegistryTools"
itemtype = "REG_DWORD"
mustboot = "Log off and back on, or restart your pc to" & vbCR & "effect the changes"
enab = "ENABLED"
disab = "DISABLED"
jobfunc = "Registry Editing Tools are now "

'This section tries to read the registry key value. If not present an 
'error is generated.  Normal error return should be 0 if value is 
'present
t = "Confirmation"
Err.Clear
On Error Resume Next
n = WSHShell.RegRead (p)
On Error Goto 0
errnum = Err.Number

if errnum <> 0 then
'Create the registry key value for DisableRegistryTools with value 0
        WSHShell.RegWrite p, 0, itemtype
End If

'If the key is present, or was created, it is toggled
'Confirmations can be disabled by commenting out 
'the two MyBox lines below

If n = 0 Then
        n = 1
WSHShell.RegWrite p, n, itemtype
Mybox = MsgBox(jobfunc & disab & vbCR & mustboot, 4096, t)
ElseIf n = 1 then
        n = 0
WSHShell.RegWrite p, n, itemtype
Mybox = MsgBox(jobfunc & enab & vbCR & mustboot, 4096, t)
End If

Method 4 : Heres the script given in italics below. Just copy and paste in a notepad. Name the file as "editregenable.reg". After you get the file just right click and select merege. Then restart the computer:

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System]
"DisableRegistryTools"=dword:00000000

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System]
"**.del.DisableRegistryTools"=-

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Group Policy Objects\LocalUser\Software\Microsoft\Windows\CurrentVersion\Policies\System]
"DisableRegistryTools"=dword:00000000

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Group Policy Objects\LocalUser\Software\Microsoft\Windows\CurrentVersion\Policies\System]
"**del.DisableRegistryTools"=-

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer]
"NoSaveSettings"=dword:00000000

The effects are usually instant, else it works after restarting your computer .

Now try to open the registry editor and see if it works.

Note: If none of the above methods works or your registry editor again gets automatically disabled say after restart, then it is highly likely that there is a virus present in your system. Hence it is recommended that the virus is first removed and then the above steps are performed.

Firefox cannot access internet / Other web-browsers e.g. IE can / Firefox cannot access internet after update / Firefox “network timeout” error.

After I myself faced a series of connectivity issues with Firefox I thought of writing this blog. This will hopefully summarize some of the many solution approaches to fix the problem.

When Firefox opens, mostly it gives the following message:

Unable to connect

Firefox can't establish a connection to the server at forums.mozillazine.org.

* The site could be temporarily unavailable or too busy. Try again in a few moments.

* If you are unable to load any pages, check your computer's network connection.

* If your computer or network is protected by a firewall or proxy, make sure that Firefox is permitted to access the Web.

This can happen due to many reasons:

• Your browser may have been hijacked by spywares, adwares, or other such malwares.

• Due to plugin errors, incompatible themes or clash with a third party software.

• Severe corruption in Windows registry.

• Firefox installation might have got corrupted somehow.

• Due to virus attack.

• Incorrect proxy settings.

• Due to modification done in the windows host file

• Crashed TCP/IP.

• Misconfigration in the firewall.

• Firewall that recognizes that Firefox restricts it silently even if it is disabled.

• Sometimes this problem appers if the firewall is not uninstalled correctly.

• Besides this there can be many other reasons (covered below).

Before trying out the various approaches, make sure that your Internet connection is working properly working. To find this:

Open a DOS command window [Run → cmd] and try pinging the google website. Ex:

C:\>ping www.google.com

A successful ping request will verify that a computer's network interface card, it's drivers, and the operating system's TCP/IP implementation are all functioning correctly. In brief it checks if network connections are intact.

Once you are sure that your connection is fine, you can proceed.

Some of the common Firefox connection issues with their resolutions are stated as under:-

1. Incorrect Proxy settings

The most common problem observed is due to incorrect proxy settings. If you using a proxy service and that you are able to connect/browse from IE, then this can most likely be causing the problem. In such a case make sure that the IE proxy settings match to that of Firefox proxy settings.

In IE go to:

Tools menu -> Internet Options -> Connections -> LAN Settings

In Firefox it’s in:

Tools menu -> Options -> Advanced -> Network -> Settings button in the connections section

(If the settings vary, then copy-paste the proxy settings info, from IE to Firefox)

Now restart Firefox.

2. Try flushing Windows DNS cache

   If repeated attempts fail to open a website, Windows may have cached an unsuccessful DNS lookup attempt. This means that you may not be able to view a particular website until the cached result expires. As a workaround, you can flush the DNS cache then try loading the site again.

• Start -> Run -> type cmd

• ipconfig/displaydns and press Enter (this will display DNS info)

• now in command prompt, type ipconfig /flushdns and press Enter (this will clear the DNS info)

• Now restart Firefox and check if it works.

3. Clear Firefox’s own internal cache

• open Firefox -> Tools -> Clear Private Data (Check the cache) and click “Clear Private Data Now”

• Now restart Firefox and check if it works.

4. Firefox may still be working in “offline mode”.

To turn off offline mode:

• Uncheck this option from File menu -> work offline

• Now restart Firefox.

5. Problem due to persistent connections.

We can disable this in the following way:

• Open a new tab, type: about:config, press Enter

• Click "I'll be careful, I promise!"

• Search for the value: network.http.keep-alive

• Right click on this value and click "toggle" to change it to false

• Restart Firefox

6. Due to third party tools e.g. Firewalls, Security Suites, etc. / Due to ‘up-gradation of these Security Utilities’ / Due to ‘Up-gradation of Firefox’ in presence of any security software can cause such problems.

• Often downgrading Firefox (Say, if prior to its upgrade it was working) to previously installed version solves the problem.

• Uninstall “completely” any security software e.g. Norton firewall, Zone Alarm Firewall, etc. as this may be blocking Firefox.

• If you are still keeping such security suites, then check the permissions given to Firefox in your firewall settings. See that it’s not restricted. Else, you must reconfigure the firewall to permit access to Firefox.

• If un-installation of security suites doesn’t work, then there can be a possibility that the un-installation still has some leftovers. To find this:

Download Enum Process.

• After downloading, execute EnumProcess.exe.

• Select Run.

• In the drop-down menu to the right, select Simple.

  This will list all the running firewall processes in red color font. Any such listed processes must be removed.

  (Do a further work-around yourself, to find way how to remove such processes.)

  You can find some help here:

• http://support.mozilla.com/no/kb/Firewalls

• http://kb.mozillazine.org/Firewalls

Once you have removed such processes then try to open Firefox.

7. If connection settings are not remembered

Certain software may be is overriding your connection settings. To remove the override:

• Open the profile folder, in “../program files/Mozilla firefox”

• Open the user.js file for editing.

• If there is no user.js file, you don't have any overriding settings, so this isn't the problem.

• Remove any lines that have the word "proxy" in them.

• Save the file.

• Restart Firefox

8. Problem due to Ipv6

Firefox uses IPv6 by default. You can disable IPv6 and see if it helps.

• In the url, type about:config, and press EnterReturn. Then click “I'll be careful, I promise!”

• Search network.dns.disableIPv6

• If the value is false, double-click on it, to change the value to true.

“If the value is already true, IPv6 is already disabled, so it isn't causing your problem.”

• Close and restart Firefox

  If disabling IPv6 doesn't resolve the problem, re-enable IPv6 by setting the preference back to false.

9. Clean install Firefox

• Uninstall Firefox completely.

• Delete any leftovers in ‘../Program files/’ folder, i.e. delete the folder ‘Mozilla Firefox’ from there.

• Clean the windows registry using a good registry cleaner.

• Reinstall Firefox, and try again.

10. Many times viruses corrupt the registry settings causing Firefox not to operate correctly.

• For this use a good scanner. You can try scanning with the following:

• Kaspersky Anti-virus

• PC Tools Spyware doctor

• Spybot Search and Destroy

• If viruses/adware/etc. are detected. Then after removing, you must clean the registry.

• After this, go ahead with a fresh installation of Firefox.

• Also, perform steps as in #11. (See below)

11. Spyware/viruses can cause to malform LSP or corrupt TCP/IP and/or Winsock registry entries.

• To solve the problem download the utility “XP TCP/IP Repair”.

• Do the repairing with it and restart system to take effect.

  This is a very important fix that one must try.

12. Issues in customization and preferences.

• Start Firefox in Safe Mode.

• "Firefox Safe Mode" window appears, containing some troubleshooting options. Check the boxes, "Reset toolbars and controls" (this is to remove any toolbar customizations) and "Reset all user preferences to Firefox defaults" (this will remove any user-set preferences and restores the default theme).

• Next, press the button, "Make Changes and Restart".

13. Extension and theme issues

Sometimes its all due to a problematic extension. Start Firefox in Safe Mode.

When the "Firefox Safe Mode" window appears, press the button, "Continue in Safe Mode". (This will start the program with all extensions disabled and with the default theme.)

If the problem goes away in Safe Mode:

• Update or uninstall the added theme or select the default theme in "Tools → Add-ons → Themes".

• Update or selectively disable or uninstall your added extensions in "Tools → Add-ons → Extensions"

14. Due to windows HOST file

A special Windows file called the "Hosts" file and its use to control Internet browsing.You can find this in the folder \Windows\system32\drivers\etc\, with the name "hosts.sam". A hosts file has the ability to redirect Internet requests.

These host files sometime gets modified due to viruses and this can effect our browsing.

Review your hosts file to see if it contains any entries other than 127.0.0.1 localhost. If it does, then make the necessary editing.

The orignal windows host file looks likes this:



You can google up and find more information regarding how to edit a host file.