Mega Shutdown and Restart Troubleshooting Guide
3D PROPHET 4500 VIDEO CARD
Other video cards that have created problems are those based on the Kyro II video chip, such as the Hercules Prophet 4500. PCBUILD subscribers have reported that until they removed the Kyro II / Prophet 4500, they could shutdown, hibernate, or go to stand by just fine, but Restart wouldn't work - it would shutdown Windows instead. Others with this video card have reported this strange behavior on both restart and shutdown.
Apparently, this problem is now solved. Microsoft reports that new drivers for this card, specific to Windows XP, are now available from Hercules. At present, they remain uncertified (PowerVR, who makes the Kyro II chip, is working on that), but they reportedly work just fine. Download the Kyro II drivers here