1. Perform a disk integrity check by clicking 'Start,' then 'Run,' and then typing 'chkdsk C: /f' (without quotes). If you are prompted to restart your computer, press the 'Y' key followed by the 'Enter' key on your keyboard.
2. Perform a complete registry scan, if the problem still exists, using a program like Registry Mechanic or Registry Easy. If any errors are detected, correct them and restart your computer.

3. Use the Windows installation disk, if the Microsoft errors reoccur, and boot with it by inserting it in your optical drive and rebooting your computer.
4. Wait for the setup to initialize, accept the License Agreement that appears and press 'R' when you get to the screen where Windows found an existing installation and offers a repair option.