Hi,
Let me know the existing operating system you are working with.
Step 1) Check for any integrity violations:
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
Step 2) Check your hard disk for any errors:
- Click Start.
- Type: CMD, from the results, right click CMD.
- Click 'Run as Administrator'.
- At the Command Prompt, type: chkdsk /r.
When you restart your system, your computer will be scanned for errors and attempts will be made to correct them.
Important: While performing chkdsk on the hard drive if any bad sectors are found on the hard drive when chkdsk tries to repair that sector if any data available on that might be lost
Hope it helps