Blue Screen Problem

Howdy guys.
Here's my system.
CPU: Pen D 805 / Zalman Copper cooler
RAMC2 4200 DDR2 512MB*2
M/B: ECS 945P-A
PS: Ultra xConnect 600W
VGA: ATi Radeon x1600 PRO 512MB DDR2
HDD:WD 250GB SATA/WD 60GB IEDE
ODD: LG SuperMulti DVD

About half year after I built my system, Blue Bcreen came up.
Very randomly, not periodically.
I don't know what it cause or under what condition/control brings the B/S.
I let my pc on to download something then sometimes next morning there was B/S.
Ot sometimes, I was just surfing web and all of a sudden B/S came up.

The B/S said one of few messages, but mostly talked something about "BAD_POOL_HEADER".

I tried format HDD and install fresh XP.(tried two different XP)
I swapped HDD, format,install fresh XP.
Tried check disk, defragment.
All virus check, spyware/worm check.
Install latest drivers for video,lan,sound.
Bought new memory(PNY, PC2 5300 DDR2 1GB) and swap.

BUT still have that B/S!!! IT is real BS!!

Anyone knows what to do????


PS: I'm gonna buy new video card and try it on my pc.....T^T
But I'll buy it fromlocal shop so in case I can return it.
which videocards you guys prefer?????
I was looking GeForce 7800GT but it has 256MB DDR3....
My current Radeon has 512MB DDR2....hm...

you guys disabled indexing services?

that is lots of errors, I think you got corrupt drivers or something like that

I have the Radeon 9600XT. Microsoft said the hardware is not compatible with the XP Pro. Try removing the driver and do all the neccessary updates and installation then reload the driver for the video card from Microsoft . This is only a temp remedy for installing and doing the updates you need. Once you install the video driver the errors come back. There has to be a solution out there.