BSODs completely at random; started after recent driver updates

[alarm siren]

Basically, This computer has always been very stable, but now it seems to BSOD completely at random, and I'm at a complete loss as to why.

The time after which these problems started was when I went through and updated a host of drivers and the BIOS (all of which, having been neglected, were hideously out of date). I had also just installed a new Asus Xonar sound card.

Initially I thought it was going to be the new sound card, so I ripped that out and uninstalled it's drivers. Problem didn't go away.
Tried switching off some of the integrated hardware the BIOS had turned on when it got updated (serial port, extra sata controller etc), and again, uninstalling the drivers for those. No luck.
Had a look at the crash dumps in WinDbg, which weren't terribly helpful as they always pointed to "ntkrnlmp.exe" (which as I understand it is the very core of the Windows Kernel) and faulting process seems to be equally as random as the time it happens - over the five times it's happened, it's been steam, msn, skyrim and "System" twice.
I tried reinstalling windows a-fresh (on my nice new SSD), install clean copies of all the latest drivers directly from the Motherboard manufacturer's website (and AMD in the case of the graphics): Low and behold! It still BSODs. All I can conclude is that ONE of these drivers is faulty somehow (or possibly the BIOS, I havn't tried downgrading that), but I can't work out for the life of me which one, and the few I've tried uninstalling have made no difference.

My only inkling is that it seems to happen most frequently when there is a disk access (like saving a game, or me moving some files around), so maybe it's to do with that?

Conclusion: Please help?

 

[alarm siren]

Is it possible to get some help on this? I'm literally at my wits end...

I tried another fresh install, and this time I didn't download any drivers, used only the ones that came on the discs, so very out of date, but also "known" good drivers. STILL got the BSOD (I can get a dump for that one too, if you want it), though this time the problematic process was dxgmms1.sys. Every single time it's always an error 38 "BUGCHECK". After this latest crash, I think it corrupted something else and I can't get in except in safe mode. If I try to boot normally, it gets to the desktop and 2 seconds later insta-hangs. No BSOD, no errors, it just... stops. I tried reinstalling all the drivers from Safemode, no effect; tried disabling startup processes, and it just made it hang during the windows logo bit of the boot phase before you reach windows login; tried system repair and system restore, no effect.

If it is, as I am starting to now suspect, a hardware problem more than a software one, then I need to know what's causing it. Don't want to waste money replacing things unneccessarily. If it is a driver problem then, again, I need to know which one because all of my own attempts thus far have failed to come up with anything concrete.

I am literally " " close to throwing the whole thing out the window.