SFC -System File Checker - Instructions
Click on Start > All Programs > Accessories
Right-click on the Command Prompt entry
Select Run as Administrator and accept the UAC prompt - the Elevated Command Prompt window should pop up.
At the Command prompt, type
SFC /SCANNOW
and hit the Enter key

Wait for the scan to finish - make a note of any error messages - and then reboot.
Copy the CBS.log file created to your desktop (you can't manipulate it directly) and then compress the copy and upload it to your SkyDrive (http://skydrive.live.com ) and post a link to it so that I can take a look.