PC Re-Boots After Upgrade

[si007]

I just upgraded my CPU and Ram, both of which are compatible with my mobo, and now my PC re-boots after about an hour. It seems to run fine up until that point. Can anyone tell me why this is happening?

Cheers.

Si

Windows XP Pro SP2
Pentium 4 3.0MHz 800FSB (Prescott)
Gigabyte 8KNXP (Rev 2) Motherboard
1 GB Corsair PC3200 Ram (Dual Channel)
Gainward GeForce FX 5900XT x8 AGP 128MB DDR
40GB WD Hard Drive 7200rpm (C Drive)
120GB WD Hard Drive 7200rpm (D Drive)
120GB WD Hard Drive 7200rpm (E Drive)
120GB WD Hard Drive 7200rpm (F Drive)
LiteOn 52x24x52 CD-ReWriter
DVD-Rom
SB Audigy 2

 

[Triton]

XP executes an automatic restart in the event of a system failure. This can be turned off.
"Disabling the “restart on system failure” feature may permit the exact cause to be isolated"
http://aumha.org/win5/a/shtdwnxp.php

Check the XP Event Log for details of the error causing the shutdown.
http://www.windowsnetworking.com/j_helmig/wxpevent.htm