Dragon+, WinXP and shutdown issues

I just upgraded my sister's system to win xp pro from win 2k pro and now she can't shut down her computer. Every time she tries, the computer just reboots. Here are some system spec:

XP 1900 (stock)
Soyo K7V Dragon+
512MB Crucial PC2100
Visiontek Xtasy 6564 GeForce3 Ti200
420w Silent TTGI PS

Before installing XP, the system worked flawlessly. Anyone got any idea what's up? Oh yeah, using the latest BIOS too (thought that might solve the prob but it didn't).

~THT

be sure to go online and get all of the windows xp updates from the microsoft site. most xp probs ive had have been solved by that so far.
this ones kinda of a long shot since you said it shut down properly with win2k, but make sure in the bios the "state after power failure" is set to "off" and make sure your reset and power buttons are attached to the mobo properly.

I've had much of the same problem with Windows XP. I've installed the latest Bios, updated the software from Microsoft, made sure all my drivers were certified by xp.

I've bought a new power supply,Sparkle 350w 220 combined power output. Yet when I'm playing Links 2001 golf sometimes the machine unexpectedly shuts down and reboots.

Could it be the Soyo motherboard? I am so frustrated I'm thanking about installing Winows 98se.

System is 1800 xp, soyo motherboard, 512 ddr 2400 ram, gforce3 ti 200 64 megs. Latest drivers from nvidia.

What can I do to solve this problem!!!!!!