New build just shuts down after a couple minutes

[ks1]

Hi everyone, my problem is that my newly built computer wont stay on long enough to install windows, the farthest i have gotten is the first time it started, I got to formatting the hard drive and it got to about 7 percent before shutting down. After that it just shuts off randomly after a minute or two. The weird thing is, is that while i am in bios it will stay on indefinitely, that is, if the computer doesent turn off before that. I have already reseated my processor, i took it out cleaned it and heatsink with iso alcohol and applied artic silver 5. I would really appreciate any help. My specs are:

cm stacker stc-to1
coolmax 650w
amd athlon 4000+
evga 7800gtx
asus a8n32-sli deluxe
2 gigs corsair xms
western digital 250gb sata
creative soundblaster x-fi platinum
two vantec fans and about 4 others

 

[bushwhacker]

Did you put your sata on RAID? Put your SATA in SATA1 and try again.
Take 1 stick of memory out and try again, do same to sound card.

 

[ks1]

tried your suggestions...and nothing helps

My hard drive cable is on sata 1. I tried removing the sound card and that doesent change anything. I tried removing the memory and trying them seperately and that changes nothing, the system still shuts down after 5-20 minutes. Any other ideas? I dont think the motherboard is bad but i have heard that can be the problem. I have also heard that a bad power supply, or an overheating computer can cause these random shutdowns. I think it is just a matter of correctly setting up the bios and I was wondering if anyone with an asus a8n32-sli deluxe motherboard is having these types of problems. Any help would be appreciated I really would like to use my new computer soon. Thanks.