1. Did you install the VIA 4 in 1 driver?(most IMPORTANT)

2. Check your IRQ, AGP is shared with PCI slot 1.
PCI slot2 is shared with Promise ATA-100
PCI slot3 is shared with PCI slot4
PCI slot5 is shared with AMR

3. Did you try other OS (Win2K, Win9X, RedHat 7.0...)
Linux should more stable than MS.
Do not use Windows XP (except if you can find "service pack")

4. Remove "ALL" componnets, only MB, Ram, Video, CDrom, Hdd and Fdd, reinstall OS. And install one card(with driver) at a time.

5. ***Did you change "Power supply" (most important for AMD chip)

GOOD LUCK, AND MERRY X'MAS