Blue screen after vista load bar

Hello, well about 2 months ago I built a new about 2 months ago and I just started having this problem (Everything was running perfect before this) - specs are as follows

CPU: E8400 @ 3.00 GHZ
Video card: Radeon 4850
MB: Asus PK5E/Wifi - AP
4 Gigs dual corsair ram
OS - Vista x64 bit home premium

Okay so today I was playing a PC game and every 30 sec - 60 sec the game would freeze from anywhere between 10 sec to over a minute. While it was frozen I could still move my mouse but the game was unresponsive. I thought it was just the game but it started happening while I was surfing the internet as well. What I thought was weird was that I could sometimes alt tab to another program which wouldnt be frozen but after some time that program would freeze as well. A few hours later while I was testing the game to see if it worked the computer became totally frozen and I was unable to do anything not even move the mouse. I restarted the computer but right after vista loading bar loads I get a blue screen that says beginning dump of physical memory. This constantly happens and its making it so I cant even get to my desktop.

Ive tried booting in safe mode but the same thing happens. Does anyone have any idea what the problem might be? Thanks for your help

I havent OCed im still running at stock speeds. Could it be a hardware problem? If so how do I figure out what hardware has a problem I cant even copy down what the blue screen, it finishes in like 5 seconds and the computer auto restarts.

Well, I reformatted the computer through vista disc and it seems to have fixed the problem. Thanks for your help.