Hi,
Where there any changes made to the computer prior to this issue?
Perform the following methods and check:
Method 1:
Step 1:
Please check if the issue persists in the Safe Mode. Refer to the link provided below for more information on safe mode:
http://windows.microsoft.com/en-US/windows-vista/Start-your-computer-in-safe-mode
Step 2:
I would recommend you to place the computer in clean boot and check if the error message still appears.
How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7
http://support.microsoft.com/kb/929135
**Note:**After troubleshooting, make sure to put the computer to start as usual as mentioned in Step 7 in the above KB article.
If the issue doesn’t persists when the Computer is in clean boot, then the issue is confirmed to be caused by a certain non-Microsoft applications.
Method 2:
If that doesn't work, try doing a System Scan. The scan will look for bad system files and will attempt to repair them, if possible.
a) Click the Start Button.
b) Type: cmd.exe in the search results.
c) Right-click the cmd.exe file and select 'Run as Administrator'.
d) In the CMD window, type: sfc /scannow and hit the Enter key.
e) Reboot and see if that resolves the issue.
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
Let us know if it helps.