"Failed to register the window class." message

Hi stnicholas,

Welcome to Microsoft Answers!

In order to troubleshoot the issue better, please provide more information.

When exactly do you get this error message?

Do you get the same error message after the restart?

I would suggest you to check in Safe Mode.

Safe mode is useful for troubleshooting problems with programs and drivers that might not start correctly or that might prevent Windows from starting correctly.

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 Shut Down 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'll 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.

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 your monitor. To exit safe mode, restart your computer and let Windows start normally.

For further information, visit the below mentioned link:

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

If the issue does not persist in Safe Mode, then perform a Clean Boot to find which non Microsoft program is causing the issue.

Steps to perform a Clean Boot.

To help troubleshoot error messages and other issues, you can start Windows 7 by using a minimal set of drivers and startup programs. This kind of startup is known as a "clean boot." A clean boot helps eliminate software conflicts.

1. Log on to the computer by using an account that has administrator rights.
2. Click Start Collapse this imageExpand this im, type msconfig.exe in the Start Search box, and then press ENTER to start the System Configuration Utility.
   1. Collapse this imageExpand thisIf you are prompted for an administrator password or for confirmation, type your password, or click Continue.
3. On the General tab, click Selective Startup, and then click to clear the Load startup items check box. (The Use Original Boot.ini check box is unavailable.)
4. On the Servicestab, click to select the Hide all Microsoft services check box, and then click Disable all.

Note Following this step lets Microsoft services continue to run. These services include Networking, Plug and Play, Event Logging, Error Reporting, and other services. If you disable these services, you may permanently delete all restore points. Do not do this if you want to use the System Restore utility together with existing restore points. 5. Click OK, and then click Restart.

For further information, visit the below mentioned link:

http://support.microsoft.com/?id=929135

Steps for Normal startup:

1. Click Start, and then click Run.
2. Type msconfig, and then click OK.

The System Configuration Utility dialog box is displayed. 3. Click the General tab, click Normal Startup - load all device drivers and services, and then click OK. 4. When you are prompted, click Restart to restart the computer.

 Hope this information helped!

 Thanks and regards

 Fouzan – Microsoft support

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