My AGP video card is not functioning properly, why?

In the CMOS Setup, under the Integrated Peripherals screen and set the
'Init Display First' setting to AGP slot.

If the problem persists then for windows 95/98/ME try the following
1. If possible copy the windows CD to a directory/folder on the hard drive. (you may temporarily lose access to the CD) (win ME skip this step)
2. Boot to Windows. If you cannot boot to normal mode then boot into �Safe Mode�
3. Open the device manager
4. Find the �System Devices� key.
5. Remove all entries under this key.
6. Shut down the system and restart. Windows should redetect all the devices, and set them up properly.

for Win 2K/XP
1. Boot to windows CD
2. Procede until licence agreement.
3. the install procedure should say searching for previous versions of windows, and then give an option for "Repair an existing installation" select this option and continue.