1. Place the Windows 7 installation DVD into your computer's DVD-ROM drive. Press the computer case 'Reset' button to reboot. When the startup prompt asks you to press any key, press 'Enter' to boot with the Windows DVD.
2. Click the 'Language' drop-down box and choose your language. Additionally, select your keyboard settings and timezone from the 'Keyboard' and 'Timezone' drop-down boxes. Click 'Next.'

3. Click 'Repair Your Computer' on the next window. Click the operating system that you want to repair and click 'Next.' This brings you to the main Windows recovery window.
4. Click 'Startup Repair.' Windows scans your computer for any corrupted or deleted files. When it finds the corrupted registry, it repairs it. This may take several minutes to complete.
5. Remove the DVD from your drive and reboot the computer again. Windows boots normally after the registry repairs.