2 day old build - everything new. getting blue screens of death at random. passed 1 round of memtest86 3.4 boot cd.

(1st day): windows installed easily, windows updated, drivers installed, not long after i start getting comfortable with my new system boom BSOD! got multiple different errors at different times - here is a list of different blue screens i got:
pfn_list_corrupt
system_service_exception
page_fault_in_nonpage_area
irql_not_less_than_equal - this one happened when i pushed the power button.

(2nd day): format + reinstalled vista64 no problem. instead of the supplied driver cd i downloaded everything individually from asus this time. windows updated. started up microsoft mail and half way through the new mail download BOOM.. driver_irql_not_less_than_equal

so here i am.. help!!!

thanks for any advice!

vista home premium 64bit

asus p5q-e (1201 bios)

Intel Core 2 Quad Q9550 Yorkfield 2.83GHz LGA 775 95W Quad-Core Processor Model BX80569Q9550 Retail

G.SKILL 4GB (2 x 2GB) DDR2 800 (PC2 6400) F2-6400CL5D-4GBPQ from the p5q-e qvl list.

MSI R4850-512M Radeon HD 4850 512MB 256-bit GDDR3 PCI Express 2.0 x16

antec three hundred case
corsair tx750w power supply

LITE-ON 20X DVD±R DVD Burner with LightScribe Black E-IDE/ATAPI Model DH-20A4H-06

Seagate Barracuda 7200.11 ST3500320AS 500GB 7200 RPM SATA 3.0Gb/s Hard Drive

Are you OCing?

Most of it points to faulty hardware, probably RAM. IRQL, PFN, and PAGE errors all suggest bad hardware, esp. memory.

A little Goolge-fu shows that the SYSTEM bugcheck could be display driver related.

Try running your memory 1 stick at a time. Memtest isn't perfect. Also try reinstalling your display drivers (up-to-date), or an older set if it doesn't help.

I guess some of those errors could be caused by VRAM faults, or bad installation of system services, but those are far less likely. I'd stake the farm on a bad stick o' G.Skill.

all stock, no OC. I just ran memtest for 6 hours without error. as soon as i reboot into windows i open iexplorer and it crashes with bsod "pfn_list_corrupt". i reboot and windows starts with "ati catalyst couldn't load". i don't know if i should lean towards ram or gpu. i'll try running one stick of ram. i have no replacement parts, my old box died and is 8 years old so whatever is wrong i hope i get it replaced soon (if it's hardware). i only have a few days warranty left on these parts with newegg.

Bad RAM or bad Driver.

Run Memtest overnight, 6 hours isn't always enough.

I had same thing with same proc/mobo w/ BIOS 1201. If u google around u'll find that BIOS 0803 is what works best with Q9550 or from what I read any Q9xxx processor. Anyways - worked for me and this BIOS downgrade stuff is highly annoying so I figured I'd pass it along