Blue Screen Memory Dump Crash

I built a pc a couple months ago and everything has been fine up until now. Today Firefox started crashing a lot then soon I would get the blue screen memory dump error. The crashes became more frequent and eventually when I it restarted I got: Windows XP could not start because the following file is missing or corrupt: \WINDOWS\SYSTEM32\CONFIG\SYSTEM.

I decided to just go ahead and reinstall windows. At least a couple times during the install I got the memory dump blue screen(I think) and a blue screen saying something like "if this isn't the first time this has happened you need to update your video card drivers." (How could I have driver problems if I was installing windows?

I gave up for a little bit and tried to reinstall again for the hell of it and everything went smooth. I've been using the fresh install for about 3-4 today when I started getting the memory dump blue screen crash again. What seemed to trigger it was when I would watch streamed video.

My guess is that the shitty power supply I put in it is causing this; I really have no clue though so I thought I tried to get some feedback before I shelled out cash for a new power supply.

1TB 7200 RPM 16MB Cache SATA 3.0Gb/s 3.5"
4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)
GIGABYTE GA-EP45-UD3P LGA 775 Intel P45 ATX Intel Motherboard
MSI N9400GT-MD1G GeForce 9400 GT 1GB 128-bit GDDR2
Okia ATX 420W Power Supply(extremely cheap, came with a microATX case all for $40)

Another thing about the power supply- it didn't even come with enough connectors so I have my hdd connected to the external SATA extension thing in the back of the case.

 

Does your power supply satisfy the needs of your video card? because it may not.

 

It's probably either the power supply or the ram. Check that the ram is running at the correct voltage in bios.

 

If it's not the PSU. It's the Motherboard or RAM. Put in one slot of ram at a time.

 

I had a simular problem with a PC i built a while back. After trying all the obvious causes i found it to be a software issue. As ddp said check your ram one at a time. In my case i found it was the xp i was installing as it installed ok but did not install all the correct files and when i tried a different version all worked fine.

 

Removing one stick of ram seemed to make the crashes stop. However, I tried using both sticks individually and neither of them would cause a crash by themselves. I also tried each single stick of ram individually in each memory slot on the board and got no crashes. It crashes seem to only start to occur when I have had both sticks of ram in for a prolonged period of time. So does that mean the mobo is fine? I also checked the ram voltage in the bios and it said it was running at 2.00 volts which is what is should be at. And the ram is fine too? My guess it that is in fact the power supply but I'm really want to be certain before I go and spend ~$50 on a new one.

Thanks.

ps- the BSOD error I'm getting is Bad_Pool_Caller
I ran the mem86 test and got no errors.