http://support.microsoft.com/gp/mats#tab0
Here are some of the Fix it solutions available:
Automatically diagnose and repair problems when the visual Aero Glass effects, themes, and transparencies are not working on your computer.
Automatically diagnose and repair when you cannot print, or for problems installing a printer, connecting to a network printer and related errors.
Automatically diagnose and repair problems with your CD or DVD drive when trying to read or burn media in Windows Vista.
Automatically diagnose and repair problems when the device manager does not detect your hardware, audio, USB and other devices, or when your devices are disabled or not working.
Automatically diagnose and repair problems with sound and audio on your computer or when your computer does not play sound.