Please run a full CHKDSK and SFC scan....
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
CHKDSK C: /R
and hit the Enter key.
You will be told that the drive is locked,
and the CHKDSK will run at he next boot - hit the Y key, press Enter, and then reboot.
The CHKDSK will take a few hours depending on the size of the drive, so be patient!
After the CHKDSK has run, Windows should boot normally (possibly after a second auto-reboot) -
then run the SFC.
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 (C:\Windows\Logs\CBS\CBS.log) to your desktop (you can't manipulate it directly) and then compress the copy and attach it to your reply
Please download and save the CheckSUR tool from
System Update Readiness Tool fixes Windows Update errors in Windows 7, Windows Vista, Windows Server 2008 R2, and Windows Server 2008
(you'll need to look in the details for Windows 7, downloading from the Microsoft Download Center)
Run it - The tool can take anywhere from 5 mins to a couple of hours to run (or 'Install') depending on how much it has to do, and may exit silently - it may appear to freeze for most of that time, but be patient.
The result is logged in the C:\Windows\Logs\CBS\CheckSUR.log file - and an archive …\checksur.persist.log file
Then zip the CheckSUR.log and attach it to your reply.