Verify or Validate Critical Windows Files
Whenever you install new software, it is possible (but not likely) that its installer will overwrite crucial Windows files. To protect yourself from potential problems you can use the Windows System File Checker utility to verify the proper DLL\’s are active.
To run the System File Checker, make sure you are logged into Windows as an Administrator and do the following:
1. Make sure your Windows CD is in the CD drive
2. Open Start > Run
3. Enter this command: sfc /scannow
You can read more about it here: [http://support.microsoft.com/kb/310747]