Type: CMD, from the results, right click CMD
Click ‘Run as Administrator’
At the Command Prompt, type: sfc/scannow
This will check for any integrity violations
Restart your system
- Insert the Windows 7 DVD
- Restart your computer
- When asked if you want to boot from your DVD drive, do so.
- Choose your language, click Next.
- Click ‘Repair your computer’
- Select operating system you want repair.