Error "The Disk Defragmenter is not installed on your computer" when launching Disk Defragmenter in Windows Vista

Symptoms

When you open the Properties dialog box for a local hard disk and click the Tools tab, one of the following symptoms may be seen:

• The Defragment Now button is unavailable
• When you click Defragment Now, you receive the following error message:

The Disk Defragmenter is not installed on your computer. To install it, double-click the Add or Remove Programs icon in Control Panel, click the Install/Uninstall tab, and then follow the instructions on your screen.

Resolution

• Click Start, type regedit.exe and press ENTER
• Navigate to the following location:

HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ Windows \ CurrentVersion \ explorer \ MyComputer \ DefragPath

• In the right-pane, double-click (default) and set its data as follows:

C:\Windows\System32\dfrgui.exe

• Close Regedit.exe

Automate

To automate the above, you may use the REG file (dfrgfix_vista.reg) attachment below.

• dfrgfix_vista.reg

Error "The Disk Defragmenter is not installed on your computer" when launching Disk Defragmenter in Windows Vista

Symptoms

When you open the Properties dialog box for a local hard disk and click the Tools tab, one of the following symptoms may be seen:

• The Defragment Now button is unavailable
• When you click Defragment Now, you receive the following error message:

The Disk Defragmenter is not installed on your computer. To install it, double-click the Add or Remove Programs icon in Control Panel, click the Install/Uninstall tab, and then follow the instructions on your screen.

Resolution

• Click Start, type regedit.exe and press ENTER
• Navigate to the following location:

HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ Windows \ CurrentVersion \ explorer \ MyComputer \ DefragPath

• In the right-pane, double-click (default) and set its data as follows:

C:\Windows\System32\dfrgui.exe

• Close Regedit.exe

Automate

To automate the above, you may use the REG file (dfrgfix_vista.reg) attachment below.

• dfrgfix_vista.reg

Error "Access is denied" when you try to log off an user account using Task Manager Users tab in Windows Vista

Symptom

When you use the Task Manager Users tab to log off an user account in Windows Vista, the following error may appear:

User (SessionId=2) could not be logged off. Access is denied.

Resolution

This happens if Task Manager is not running under administrative privileges. To log off an user account, Task Manager must be run with administrative privileges. Follow one of these methods:

Method 1

• Open Task Manager (taskmgr.exe) and click the Processes tab
• Click Show processes from all users
• When you are prompted for an administrator password or confirmation, type the password or provide confirmation.

(Task Manager now runs with administrative privileges.)

• Switch to the Users tab and log off an user account.

Method 2

• Click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator.
• If you are prompted for an administrator password or for confirmation, type your password, or click Continue.
• At the command prompt, type taskmgr.exe, and then press ENTER.

(Task Manager starts with administrative privileges.)

• Switch to the Users tab and log off an user account.

Unable to open .PPS attachments directly from Windows Mail in Windows Vista

Symptom

When you open a .PPS file that came as a mail attachment in Windows Mail, you may see the Open / Cancel dialog box. When you select Open, the following error may be displayed:

This file does not have a program associated with it for performing this action. Create an association in the Set Associations control panel.

This may happen even though you have PowerPoint Viewer 2003 or 2007 installed. However, the same file may open correctly when saved to disk, and then viewed. Note that this problem does not occur if you have Microsoft Office or PowerPoint installed.

This article is applicable for Windows Vista, with PowerPoint Viewer 2003 or PowerPoint Viewer 2007 installed. For a Windows XP version of this article, see article Unable to open .PPS attachments directly from Outlook Express?

Cause

This happens if the Open command is missing for .PPS and/or .PPT file types.

Resolution

To resolve the issue, follow these steps:

For .PPS files (Microsoft PowerPoint Slideshow)

• Click Start, type regedit.exe and press ENTER
• Navigate to the following branch:

HKEY_CLASSES_ROOT\PowerPointViewer.SlideShow.11\shell\Show

• Right-click Show and click Rename
• Type the word Open so that Show is replaced by Open command
• If you have PowerPoint Viewer 2007 installed, repeat the above steps in this key, as well:

HKEY_CLASSES_ROOT\PowerPointViewer.SlideShow.12\shell\Show

• After changing Show to Open, close Registry Editor window.

For .PPT files (Microsoft PowerPoint Presentation)

• Click Start, type regedit.exe and press ENTER
• Navigate to the following branch:

HKEY_CLASSES_ROOT\PowerPointViewer.Show.11\shell\Show

• Right-click Show and click Rename
• Type the word Open so that Show is replaced by Open command
• If you have PowerPoint Viewer 2007 installed, repeat the above steps in this key, as well:

HKEY_CLASSES_ROOT\PowerPointViewer.Show.12\shell\Show

• After changing Show to Open, close Registry Editor window.

Screenshot

(Fig 1) Show is renamed as Open

Error "Access is denied" when you try to log off an user account using Task Manager Users tab in Windows Vista

Symptom

When you use the Task Manager Users tab to log off an user account in Windows Vista, the following error may appear:

User (SessionId=2) could not be logged off. Access is denied.

Resolution

This happens if Task Manager is not running under administrative privileges. To log off an user account, Task Manager must be run with administrative privileges. Follow one of these methods:

Method 1

• Open Task Manager (taskmgr.exe) and click the Processes tab
• Click Show processes from all users
• When you are prompted for an administrator password or confirmation, type the password or provide confirmation.

(Task Manager now runs with administrative privileges.)

• Switch to the Users tab and log off an user account.

Method 2

• Click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator.
• If you are prompted for an administrator password or for confirmation, type your password, or click Continue.
• At the command prompt, type taskmgr.exe, and then press ENTER.

(Task Manager starts with administrative privileges.)

• Switch to the Users tab and log off an user account.

Unable to open .PPS attachments directly from Windows Mail in Windows Vista

Symptom

When you open a .PPS file that came as a mail attachment in Windows Mail, you may see the Open / Cancel dialog box. When you select Open, the following error may be displayed:

This file does not have a program associated with it for performing this action. Create an association in the Set Associations control panel.

This may happen even though you have PowerPoint Viewer 2003 or 2007 installed. However, the same file may open correctly when saved to disk, and then viewed. Note that this problem does not occur if you have Microsoft Office or PowerPoint installed.

This article is applicable for Windows Vista, with PowerPoint Viewer 2003 or PowerPoint Viewer 2007 installed. For a Windows XP version of this article, see article Unable to open .PPS attachments directly from Outlook Express?

Cause

This happens if the Open command is missing for .PPS and/or .PPT file types.

Resolution

To resolve the issue, follow these steps:

For .PPS files (Microsoft PowerPoint Slideshow)

• Click Start, type regedit.exe and press ENTER
• Navigate to the following branch:

HKEY_CLASSES_ROOT\PowerPointViewer.SlideShow.11\shell\Show

• Right-click Show and click Rename
• Type the word Open so that Show is replaced by Open command
• If you have PowerPoint Viewer 2007 installed, repeat the above steps in this key, as well:

HKEY_CLASSES_ROOT\PowerPointViewer.SlideShow.12\shell\Show

• After changing Show to Open, close Registry Editor window.

For .PPT files (Microsoft PowerPoint Presentation)

• Click Start, type regedit.exe and press ENTER
• Navigate to the following branch:

HKEY_CLASSES_ROOT\PowerPointViewer.Show.11\shell\Show

• Right-click Show and click Rename
• Type the word Open so that Show is replaced by Open command
• If you have PowerPoint Viewer 2007 installed, repeat the above steps in this key, as well:

HKEY_CLASSES_ROOT\PowerPointViewer.Show.12\shell\Show

• After changing Show to Open, close Registry Editor window.

Screenshot

(Fig 1) Show is renamed as Open

Error "Registry editing has been disabled by your administrator" when you open the Registry Editor in Windows Vista

Symptom

When you attempt to start the Registry Editor (regedit.exe) in your Windows Vista system, you may receive the following message:

Registry editing has been disabled by your administrator

Resolution

If the above error message is shown in a standalone system, then it may be a result of Malware infection. It is also possible that the DisableRegistryTools policy had been enabled by a third-party tweak program which you may be using. It's highly advisable to follow up with a complete system checkup for Virus and Malware, especially when you're unsure about the cause.

Note: If your system is connected to a domain, your network administrator may have enabled the DisableRegistryTools Policy setting. In that case, you'll need to contact the network administrator to relax this restriction, if need be.

Method 1 - Using Group Policy Editor

If you are using an edition of Windows Vista (Windows Vista Business, Enterprise and Ultimate editions) which includes the Group Policy Editor, follow these steps:

• Click Start, type gpedit.msc in the Search box, and press ENTER
• Go to the following branch:

User Configuration | Administrative Templates | System

• Double-click Prevent access to registry editing tools
• Set it as Not Configured

Important: If it's already set to Not Configured, set it to Enabled and click Apply. Then repeat the steps and revert the setting back to Not Configured. This removes the registry based policy if set already.

Method 2

This method should work in all editions of Windows Vista.

• Download reg_enable.vbs attached at the end of this article, and save it to Desktop
• Open an elevated command prompt. To do this, click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator. If you are prompted for an administrator password or for a confirmation, type the password, or click Allow.
• Switch to your Desktop directory by typing the following command, and then pressing ENTER:

cd /d %userprofile%\desktop

• Then, type the following command and press ENTER

wscript.exe reg_enable.vbs

• Type EXIT to close the Command Prompt window.

If everything worked fine, the DisableRegistryTools policy should have been removed by now. See if you're able to launch Regedit.exe now.