What about system File Checker in Windows Vista?

Use Command Prompt   

When important System Files in Windows are deleted or damaged, to make use of System File Checker we can substitute the text that exists in the %SystemRoot%\System32\Dllcache folder.
In addition, if %SystemRoot%\System32\Dllcache folder is damaged, we can also restore the contents of the folder.
 
Please refer to the following contents.
1.Click the Start button, and then click All Programs.
2.Click Accessories.
3.Right-click Command Prompt in the schedule displayed, and then click Administer Perform.

4.After displaying the User Account Control message, click the Continue button.
For standard users, please refer to the following relative solution.
[Windows Vista] About User Account Control

5.If not displaying the User Account Control message, please refer to the following steps.
6.Input sfc /scannow, and then press the Enter Key.

The above contents will make the system scan automatically.