Can't figure out BSOD

I built a PC over last summer (june) for a friend, and it is randomly getting BSODs.

most of the time the BSOD error is: IRQL_NOT_LESS_OR_EQUAL
however other times it gives no error code and most of the time it gives no file as reference.

The OS is Windows 7 pro 64bit

I will be updating this post with info from the Windows event logs

I have run the following diagnostics with no errors at all:
memtest86+ (5 passes)
spinrite (level3)
prime95 bootable from bootzilla (2 hours)
TuffTest seek and surface tests 1 pass each

The hardware was all purchased from newegg in June of 2010.
I have been attempting to trouble shoot on and off

I have tried 3 different driver configurations:
I let Windows 7 automatically install all hardware
I ran the driver CDs included with the hardware
I downloaded the newest driver updates and applied them manually

All 3 drivers configurations still BSOD

Here is a list of the hardware and software for reference:
--Microsoft Windows 7 Professional 64-bit 1-Pack for System Builders - OEM
--Hanns·G Hi-221DPB Black 22" 5ms Widescreen LCD Monitor
--Logitech 967973-0403 Black 104 Normal Keys PS/2 Standard Deluxe 250 Desktop - OEM
--APC BE750G 750 VA 450 Watts 10 Outlets Power Saving Back-UPS
--BELKIN BE108200-06 6 feet 8 Outlets 3390 Joule Home/office Surge Protector with Telephone Protection - OEM
--Rosewill R101-P-BK 120mm Fan MicroATX Mid Tower Computer Case
--Sony Optiarc CD/DVD Burner Black SATA Model AD-7260S-0B - OEM
--Western Digital AV-GP WD5000AVDS 500GB 32MB Cache SATA 3.0Gb/s 3.5" Internal AV Hard Drive
--GeIL 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10660) Dual Channel Kit Desktop Memory Model GV34GB1333C9DC
--Western Digital Elements 1TB USB 2.0 Desktop External Hard Drive WDBAAU0010HBK-NESN
--ASUS P5G41T-M LE LGA 775 Intel G41 Micro ATX Intel Motherboard
--Intel Core 2 Quad Q8300 Yorkfield 2.5GHz 4MB L2 Cache LGA 775 95W Quad-Core Desktop Processor BX80580Q8300
--CORSAIR CMPSU-450VX 450W ATX12V V2.2 80 PLUS Certified Active PFC Compatible with Core i7 Power Supply

I have tried several BIOS tweaks relating to power saving states and suspend modes which I found on various forums with reference to this mainboard, they also made no difference. The BIOS has since been reset to defaults and it is of course running the newest BIOS update.

I am at the point now that I am getting ready to just start RMAing random hardware before the warranties run out...

That's a driver problem usually updating the driver to the latest version helps those problems. without digging deeper into the logs to find out which hardware is failing with its driver you'll have to download all the drivers for your system

I manually updated every driver last time I physically sat in front of the PC which was in November 2010. The BSODd are still happening.

If I start doing RMAs the PSU will be first, another friend of mine suggested i start with that as well.

I'm almost wondering if maybe it's just not drawing enough power?

you using on board video ?

I am using onboard video: Intel GMA X4500

and wow, i must have been in a rush when i purchased that hard drive... i can swap that out easily enough ive got 4 or 5 WD black series drives lying around

did you go to Intel's site and look for video drivers and mother board drivers for your board ? and maybe there's a BIOS update for something that's plaguing your machine.

@Hastibe: There really isn't much to disable since all the devices are onboard the mainboard

@swifty_morgan: I have tried at least 3 different drivers (from windows, from intel and from the included CD)

@alexinnes: I was running with the bios set to SPD and i realized the board is 1066 or 800 and the RAM is 1333 so i changed the RAM manually to 800.

So I have saved all the minidumps and the event log errors.

I ran a piece of software that I found called WhoCrashed, which goes over the dump files for you. It only referenced ntoskrnl.exe and ntkrnlmp.exe With various actual error codes.

ntoskrnl.exe
IRQL_NOT_LESS_OR_EQUAL
SYSTEM_SERVICE_EXCEPTION
KMODE_EXCEPTION_NOT_HANDLED
MEMORY_MANAGEMENT
PFN_LIST_CORRUPT

ntkrnlmp.exe
IRQL_NOT_LESS_OR_EQUAL

I was also able to run an extended test of prime95.
I ran prime95 with the RAM timing set at 1066 and at 800 (the ram is actually 1333 so it is being run under spec no matter what)

When running the Blend test prime95 failed at both RAM settings.

When running the Small FFTs test which stesses the CPU and almost no RAM it has not failed. This test was only run at 800.

At this point I am assuming the RAM is bad or there could be an issue with the mainboard.

I have already submitted RMA requests for the Power Supply and the RAM, but I may end up purchasing new RAM since the RAM isn't really matched to the mainboard

The OS has been installed fresh 3 times, same every time