Please Help...System shuts off after running any game.

Hey MJ ::: One item that you have to keep in mind is that when we run today's games on our baby's it is almost like benching the whole system,all that other stuff that you do is merely child's play for any of today's gaming machines,,so if your system is that new then do your self a favour and replace that power supply/or test the system with another tier 1 or 2 brand,you are not reporting any kind of error message either hardware or software oriented so there is only one logical conclusion to come to...Anyhow if it was me that would be my course of action,,otherwise you will have to troubleshoot the whole system,and you know what a PITA that will be...

Thanks for the quick response! I think it's the PSU definitely. my 9800gt was plugged into a rail 2 plug. I switched it to a rail one 6 pin PCI-E plug, that has more stuff plugged into it overall, and the computer actually turned off sooner than it usually does while running the CS:Source stress test video. My computer is pretty solid for what i paid, but it's by no means a top of the line beast. I hope there is actually something wrong with this psu, and not that it simply can't handle the power draw from the GPU when i fire up a game. It has to be the power supply, because unless i'm running a game, there's very little power drain from the 9800gt. i'll try to find a good deal on another psu, and just return this one.

Here's a few to consider:

CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI Ready CrossFire Ready 80 PLUS Certified Active PFC Power Supply - Retail
http://www.newegg.com/Product/Prod [...] &Tpk=650tx $109.99 - $30.00 MIR

PC Power & Cooling S75QB 750W ATX12V / EPS12V SLI NVIDIA SLI Certified CrossFire Ready 80 PLUS Certified Active PFC Power Supply - Retail
http://www.newegg.com/Product/Prod [...] 6817703009 $124.99 - $25.00 MIR

CORSAIR CMPSU-750TX 750W ATX12V / EPS12V SLI Ready CrossFire Ready 80 PLUS Certified Active PFC Power Supply - Retail
http://www.newegg.com/Product/Prod [...] &Tpk=750tx $119.99 - $20.00 MIR

thanks to everyone for all the help. I just placed an order for the CORSAIR CMPSU-750TX. This 60Amp rail is going to be a beast...and it definitely shouldn't shut down on me at all. I looked at my current PSU ampere rating...and it only has 19A +12V rails. Dang...i didn't know these new GPU's and CPU's sucked so much juice. My friend called me an idiot for getting an "unnecessary 750W PSU." I can't wait to tell him that my computer drew too many amps and shut itself off...so i actually had to UPGRADE. haha, that'll be fun. I just find it hilarious that i dont have nearly a top of the line system...but i need a beast of a power supply. I guess i picked out good components then! gotta love $800 budget build-your-own black friday gaming pc's.

thanks. I definitely will. my 9800gt only requires one 6 pin connector. I've tried using a connector from both rail 1 and rail 2, no dice. I find it amusing too that this 750W PSU can't handle my 9800...but i've read some reviews of my PSU and a few other people have mentioned the exact same problem i'm having. One guy even had my exact same GPU and same processor, on a Gigabyte mobo...and his would shut off seconds after starting a game. In this case, he got a "higher quality" PSU, and it has yet to shut off on him again. There really isn't any other explanation other than a faulty/incorrectly spec'd psu. my 750W Corsair should do me just fine when it arrives.