Windows 7 will not log off.

Hey Fred Gotthardt,

Thanks for posting in Microsoft answers!

a. Since when have you had this issue?
b. Any changes made to the computer recently?

Follow the below methods and check if your issue gets fixed.

Method 1:

Boot into safe mode and check if the issue exists.

To boot into safe mode, follow the below steps:

1. Remove all floppy disks, CDs, and DVDs from your computer, and then restart your computer.
Click the Start button, click the arrow next to the Lock button, and then click Restart.

2. Do one of the following:

• If your computer has a single operating system installed, press and hold the F8 key as your computer restarts. You need to press F8 before the Windows logo appears. If the Windows logo appears, you will need to try again by waiting until the Windows logon prompt appears, and then shutting down and restarting your computer.

• If your computer has more than one operating system, use the arrow keys to highlight the operating system you want to start in safe mode, and then press F8.

3. On the Advanced Boot Options screen, use the arrow keys to highlight the safe mode option you want, and then press ENTER. For more information about options, see Advanced startup options (including safe mode).

4. Log on to your computer with a user account that has administrator rights.

When your computer is in safe mode, you'll see the words Safe Mode in the corners of the display. To exit safe mode, restart your computer and let Windows start normally.

Refer the below links for more details:

Start your computer in safe mode
http://windows.microsoft.com/en-US/windows7/Start-your-computer-in-safe-mode

What is safe mode?
http://windows.microsoft.com/en-us/windows7/What-is-safe-mode

If the issue does not occur in safe mode, it indicates that one of the services or startup items may be corrupted and maybe causing the issue.

To troubleshoot the issue, you may have to put your system in clean boot.

Check the below link for more details on clean boot:

How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7
http://support.microsoft.com/kb/929135

Method 2:

Once you’ve logged into safe mode, you may do a System File Checker (SFC) scan on your computer. SFC tool scans system files and replaces incorrect versions of the system files by using the correct versions.

To run the System File Checker tool, follow these steps:

1. Click Start, and then type cmd in the Start Search box.
2. Right-click cmd in the Programs list, and then click Run as administrator.

If you are prompted for an administrator password or confirmation, type your password or click Continue

3. At the command prompt, the following line, and then press ENTER:

    sfc /scannow

Check the below link for details:

How to use the System File Checker tool to troubleshoot missing or corrupted system files on Windows Vista or on Windows 7
http://support.microsoft.com/kb/929833

Hope this helps!
Gokul – Microsoft Support