1. Insert the Vista CD into your computer.
2. Restart the machine and press any key during startup to boot from the CD.

3. Input in your language preference, keyboard type and currency type from the on-screen menus.
4. Click on the link stating 'Repair this Computer.'
5. Select your installation of Vista from the on-screen menu and press the 'Next' button. This will autodetect any errors with the OS and fix them by replacing faulty files with new ones.