Random BSOD after new processor install 000000007F

Hello all,

I thought I'd breathe a few more years of life into my old 775 rig and install a new quad-core processor. Unfortunately, this has turned into a much bigger hassle than I expected. Long story short, currently I'm able to run for several hours, but then unexpectedly I'll get a BSOD with stop code 000000007F (unfortunately I keep missing the first parameter, next time I see it I'll post with that detail.

Here are the steps that lead me to this point, as best I can recall:

-Original processor: Intel Core2 Duo E4500 @ 2.20 GHz. As far as I know, everything was working fine.
-New processor: Intel Core 2 Quad Q9400 Yorkfield 2.66GHz LGA 775 95W Quad-Core Desktop Processor AT80580PJ0676M installed. Computer did not boot, no beep code.
-Determined problem was my motherboard, ABIT FP-IN9 SLI, was several BIOS versions behind. Updated BIOS from 12 to 16.
-New problem: ABIT is no more latest BIOS is unable to accurately detect my CPU temp. First time I booted, it mistakenly read the processor temp at 92 C and shut down while Windows was booting and corrupted something.
-Switched back to E4500, attempted to boot again. BSOD during boot (the very first dump you'll see is from this event). Ran boot recovery to restore Windows. Did my best to make sure everything was OK again, even did some stress tests and made sure I wasn't getting any more BSODs. Without really thinking about it, I think I installed drivers for a Wacom Bamboo Create within this period (1/1/2013, date verified from Programs list)
-Switched back to Q9400, along with a new CoolerMaster fan just in case my old stock fan couldn't cut it. Disabled auto-shut down in BIOS. Once Windows booted again, I installed CoreTemp as a backup to monitoring my CPU temp (1/3/2013, date verified from Programs list)
-Started seeing blue screens every 30 minutes (at first it seemed like they only happened when viewing YouTube videos, but I'd also seen them happen at totally random times - often, immediately after clicking a button. On one occasion, I let Verifier run for longer than 30 minutes idle on desktop, and then as soon as I tried to open Chrome I hit another BSOD) I've also noticed other abnormalities, such as new icons added to desktop not immediately respecting auto-sort orientation) - I'm pretty certain the stop code at that time was F7, not 7F, but since those are pretty close I could be mistaken.
-In response to the above, I updated my Realtek HD sound card. No change to BSOD behavior.
-Next, I thought it was the tablet, so I uninstalled drivers for my Bamboo Create.
-Ran some stress tests after that, and it seemed like the problem was gone. Computer could be on for several hours, I could run Minecraft on the highest settings for a while, watched many Youtube videos (important since that was a suspected culprit), I even left it on overnight while uploading some videos to Youtube. Woke up and everything was peachy. I was convinced everything was fine. And then, it happened again while watching Youtube - but this time the stop code was definitely 7F.
-Uninstalled CoreTemp, as that was the next likely suspect (i.e. only other thing I can recall installing during this experience). Same behavior as above, another 7F BSOD hours later.

I'm currently in the state described in the last step. I can run for several hours and perform quite a lot of work, but inevitably I'll see it crash with 7F. It's not just Youtube either, last time it happened while playing 'I Wanna Be The Guy' (a Shockwave app for those unfamiliar) and recording with Afterburner simultaneously. However, there was a second BSOD immediately following that one, as Windows was rebooting it seemed like the monitors went into power saver mode before showing me the login screen. I moved my mouse, and oddly enough it did bring back the login screen - though obviously corrupted. It looked like certain graphics hadn't loaded and fonts were in a console plaintext. I only saw it for a moment before another BSOD replaced it (I don't think these last two got logged - the dates in the last files from the Grab All are 1/12)

I'm not sure where to go from here, short of returning the processor/buying a new motherboard. I just ran Memtest86+, all four RAM sticks passed all tests at least twice. There are too many unknowns for me right now to justify another purchase just yet. Did the boot recovery totally fix the system corruption from the forced shut-down? Did the Wacom drivers corrupt something that wasn't entirely cleaned during uninstall? Is there more wrong with my BIOS than simply misreading the temperature (note: I've already considered flashing to Beta 18, but I've heard reports that Windows 7 users see frequent BSODs with that version so I don't think that's an option)? Any help would be greatly appreciated.

SF Diagnostics report attached

Thanks for the fast (wow, almost instantaneous) reply!) I followed those steps, cleaned out 6 troublesome files (one of them was a trojan) and it's been smooth sailing since. Can't be completely certain everything is fixed due to the sporadic nature of this issue, but it's been running about 10 hours straight with near-constant activity and no BSODs yet.

Unfortunately, there's nothing I can do about the BIOS. Abit is out of business, meaning the only upgrades available for my mobo is either their Beta 18 or something customized by an end user - and Beta 18 has been reported to BSOD with Windows 7.

Out of curiosity, any idea why Avast would suddenly start exploding after changing the processor and/or BIOS? I've been using it for a few years and never had any problem with it. Obviously, that trojan could have been a factor, but is there another cause?

Nope, two more blue screens, one right after the other... first one was 7F (D), and after that I turned the PC back on and immediately went back to the same activity as before, and only 15 minutes later saw a 7F (8). Very strange it seems like it can sit and do virus scans all night long, but if I do anything requiring user input for any length of time I'm bound to see it happen. Almost wondering if it's mouse/keyboard/joypad related now.

I re-ran the diagnostics tool and made a new update. I also have a kernel dump from the last crash, not sure how/where to upload that or if it's necessary.

Might be unnecessary - I think I fixed it by upgrading to the Beta 18 BIOS for my motherboard. I have an ABIT FP-IN9 SLI, and I was running BIOS 16 which seems to have a glitch causing it to misread the CPU temp for 45 nm chips. I had worked around it by disabling auto-shut down in my BIOS, but the BSODs may have been caused by a heat protection system I missed. My theory is that the BIOS was lowering my CPU voltages to unstable levels in an attempt to cool down a processor that wasn't really overheating.

I was afraid to upgrade to 18, because while I knew it would fix the temp misread, I also read several reports of it BSODing Windows 7 - so, I thought I'd just have another flavor of the same problem. However, someone suggested the cause of 18's instability was actually a different bug that was causing it to apply less voltage than you actually tell it to. They worked around that issue by manually tweaking the voltages, setting them near the upper bounds of their CPU's recommended max so they'd fall towards the middle. I did the same, and so far my rig's been passing stress tests which I'd previously determined were surefire ways to trigger the BSOD. Still a little early to call it, but I'm up to 6 hours of constant user input and no problems yet.

I'd like to give it a couple of days before I mark the thread as solved, just in case. If you're interested, I could post my BIOS settings, even though that would only help a handful of people with my exact hardware issue, and I realize this isn't necessarily a hardware forum :) More information can be found here, where I posted an earlier issue related to the same problem:
FP IN9-SLI - New CPU instantly overheats

And of course, thank you very much for your help!

Feels pretty stable now, so I'll mark this solved. Thanks a lot for the advice!