Wiindows XP BSOD

Hi.
Basically i've been having a barrage of blue screens lately, during seemingly random operations.
The vast majority of the time (read: the ones i can remember) it's been a IRQL_NOT_LESS_OR_EQUAL error. Now through some limited research i found that this is usually a driver error (right?) and that the idea is to get rid of the latest piece of hardware until you narrow down the offender.
Unfortunatly everything bar the harddrive is new. =(
Is there anything that I can use to find what is causing this error? I tried a Microsoft memory-test programme and that didn't come up with anything so I'm assuming it isn't that.
Any other ideas?

XP has the biggest fit when there is something wrong with the graphics card or graphics card drivers. Have you tried swapping for a completely different card? How about different drivers (if possible, try the generic drivers for your card's chipset instead of the manufacturer-specific ones and see if that makes a difference)? Even a brand new graphics card can be faulty, or have sucky drivers (Radeon cards are particularly bad for this BSOD, apparently).

I've tried alternating between the manufacturer's graphic drivers and the fabled Omega drivers. Neither have stopped the problem.
Recently games have been hanging. I basically have played three games in the past... month or so. Half Life 2, which seems fine, Psychonauts demo (which froze twice) and Darwinia (again, froze twice). I'm not sure if this is connected.
Anyway, I gave a bit of bad information above, I said that only the harddrive was old. Infact my graphics card, a Radeon 9800 Pro, was also moved from my old computer. I'm guessing that this means it can't be that... But I don't know. I fail to see what else it could be...

I still wouldn't discount the possibility of it being the card. A card might be fine on one type of motherboard but throw a wobbly on another. There's also the remote possibility that it was static damaged when moving it from old machine to new (you should also check and clean the contacts for good measure). Again, try with a different card (even just a cheap one) if possible. Are these BSODs only occurring in games? That could be bad memory on the graphics card, or some other chip gone bad, or even something as simple as a cooling issue (that wouldn't occur much during office/internet/general stuff, since it's only games that put the biggest strain on the card). Whatever, I would still strongly recommend eliminating the graphics card from the equation first, as it seems to be the likliest candidate. Also, turn off any memory acceleration options in the system BIOS (shadowing, cache, "high performance" modes) - it's worth a try at least.

It doesn't just crash on the games, sorry if that was unclear. It will be at seemingly random times/situations.
I'll see if anybody i know has a scrappy graphic card they'll let me use and give it a go.
I will also disable those BIOS options if they're currently on.
Thanks. :)

Right. After downgrading from the Radeon 9800 to the old Geforce 2 i thankfully still had, all seemed to be going well. For about four/five days the computer seemed pretty unstable.
THEN yesterday it began crashing again. Twice now i've had it go to the BSOD. One time a PAGE_FAULT_IN_NONEPAGED_AREA error, the other time an IRQL_NOT_LESS_OR_EQUAL.
i'm thinking that i should take out one of the two RAM chips i have, testing it for a week or so, then swapping over to see if it's one of those that is doing it.
Any other suggestions?

Yep, go with swapping the memory. These BSODs are a bastard to nail down, so you've got to do it logically, changing one thing at a time.

And that's where i got shit-crazy, haha. :D
tomorrow i'll be getting my new hard-drive, so i'll take out a stick of RAM and see what it does.

I somehow managed to get a corrupted filesystem (least that's what I /think/ it was) when I was running XP. Damn thing kept BSODing every time it tried to write to the affected area, and repeated reboots and attempts to reinstall without reformatting just seemed to make it worse. It went from dying when I was in the middle of something to dying when it tried to boot to dying during the install process. I had to go to a friend's house and download Knoppix so that I could boot up and send my important stuff over the network before slapping down the ban hammer on Windows.

I only had the damn thing because I was too cheap to buy a router to replace the shitty Windows only USB modem my ISP sent me. I've now learned my lesson and overcome my cheapness.