possible motherboard problem?

i just got my new system put together today (see sig) and when i try to boot up it gets to the windows loading screen and then reboots. however, if i have the windows xp installation disk in it boots up fine...what is going on?

Mate,

What is your PCI-E Freq? Try setting it to 102MHz and see if it helps. Also, I hope you ahve disabled K8 CnQ.