1. Click Start, click All Programs, click Accessories, right-click Command Prompt, and select Run as Administrator.
2. Click Continue or supply Administrator credentials if prompted.
3. In the Command Prompt window type the following, and press Enter:
sfc /scannow
Note the gap... it should be there.
4. You should see the following on-screen messages:
Beginning the system scan. This process will take some time.
Beginning verification phase of system scan.
Verification % complete.
5. Once the scan has completed you will receive an onscreen message resembling one of the following:
…found no integrity violations
…found corruption but repaired it
…found corruption that it could not repair
Please reply back here with the completion message that you received.