Computer problems

[Opio]

Hey, I recently built a computer by ordering the parts separately, from various vendors. My computer has not been running well at all.. it restarts randomly on its own, and just a few days ago it restarted and reset the bios, which took me 8 hours of messing around with the bios for it to recognize my ATA hard drive and get back into windows. I built the computer for gaming, I play return to castle wolfenstein, and I'm pretty new to overclocking. I need to get my computer to stop restarting.. because sometimes it restarts in the middle of a scrim/match which is really annoying. Some more info about my computer: I got the case from www.xpcases.com .. its the Aluminum Blue X-Superalien ATX PC Case with 500 Watt P4/AMD Dual Fan Power supply. I use one gig of dual channel 400hz pc3200 corsair platinum ddram, radeon 9800xt with the latest driver, and a pentium 4 2.8 ghz with hyper threading processor. OS is windows xp pro, but without service pack one (hopefully gettin SP1 soon). My friend thinks the reason it is continously restarting on its own is because of the power supply; the 12 volt line isn't actually at 12 volts, its between 11.75 and 11.85 most of the time. If anyone has had this problem before or can help me fix this, any info would be greatly appreciated. Thanks.

-Opio

[caboob]

Is this happenning at stock speed or overclocked?

[Opio]

This is all at stock speeds. I wasn't going to overclock until I got a custom heatsink.. I'm not sure how much my memory can handle.

[caboob]

What mobo do you have?

It's possible that your mobo may be undervolting. Mine does and I had to increase the Vcore a notch to get stability under load at stock. Those voltage readings seem low, the mobo may be reading it inaccurately...only way to know for sure is to hook it up to a multimeter. I also get readings in that range as well, even overclocked.

[RCtruckguy]

i think the 4.1v drivers for the 9800pro dont work good and cause instability, check in the vid card fourms to be sure. try 3.7's, i think those are the best ones for now

~Alex

[Opio]

Oh yeah.. forgot to say what motherboard i got... It's the dfi LanParty 875p. My computer hasn't crashed much in the last few days, also.. what is a mutimiter? vcore?