Random reboot/BSOD when playing WoW, Minecraft, watching VLC videos

My machine is a custom built gaming rig and is a little over a year old (March 2013). Up until a couple months ago, I had no problems with it randomly rebooting. But, as the title says, recently it has been randomly shutting down and starting back up approx. 3 seconds later while using it, no BSOD or warning beforehand -- simply instantly shutting down, waiting a few seconds, then booting up again, all without my invoking it. It has happened a small number of times when doing light computer activity (browsing web, typing up a document), and a couple times when I've left it running while away. It mostly happened when playing Minecraft or watching some TV shows in VLC Player (Family Guy, not anything HD), activities that are not very strenuous for the computer. This computer was built for gaming and has been used for such, with lots of time put into Guild Wars 2, Battlefield 3, and plenty of other power-hungry games that it was built to withstand, all without any of the random rebooting problems.

I was beginning to get very frustrated, because the Event Viewer showed no detailed information whatsoever. As the only option my technologically intermediate mind could think of, I opened my machine's case and dusted the heck out of it with a can of compressed air and checked all connections to make sure they were firm, fastened, and secure. That seemed to cure it for a few weeks.

A couple weeks back, I began play World of Warcraft and have been fairly heavily since then (several hours per day). The few weeks before that, after cleaning my machine, there had been maybe one or two random shutdown/reboots. In fact, up until this evening, it seemed to be running fine in general. But, sure enough, I was in the middle of playing WoW tonight and the computer unexpectedly shut down and rebooted a few seconds later. Thinking it was a fluke, after it finished booting I started up WoW again, and a few minutes later, it shut down a second time.

I did some googling and came upon this post instructing usage of the driver verifier to see if it can cause some sort of BSOD or dump file (the green text in said post), because the random shutdown/reboots that have been happening did not produce any sort of BSOD or dump files. Following what that post said, I used the driver verifier, and after rebooting, a few seconds into showing the desktop, a BSOD appeared (and got stuck on the "initializing disk for crash dump" part, never rebooting or going past that after 10-15 minutes, long enough for me to take a photo of it). This leads me to believe there is a problem with one of the drivers that is causing this malfunction, but I do not know how to figure out what the source of the problem is.

The linked photo shows this for the BSOD error message (copied from the photo, so I hope it's correct):

*** STOP: 0x000000C9 (0x0000000000000224, 0xFFFFF88006502710, 0xFFFFF9800E9328B0, 0xFFFFFFFFC00000BB)

*** HIDCLASS.SYS - Address FFFFF88006502710 base at FFFFF88006500000, DateStamp 51d3a2f1

As per the posting instructions, the DM Log Collector's resulting .zip file is attached. If any other files are necessary to figure out the culprit, I'm all ears, because I want to get this remedied ASAP. It's eating into my dungeon time in WoW. :P

Additional notes: it's not an overheating problem; CPU hits max 65C and GPU a little below that, both fan cooled (I have WoW capped at 60 fps so it doesn't run too hot). I have no overclocking whatsoever.

Quick edit: I ran /sfc scannow when this first started happening a few months ago, and no problems were found. Additionally, Memtest86+ found no problems.

Another quick edit: after typing this up, it shutdown/rebooted for the third time this evening, while I was doing nothing but light web browsing.

Any additional information needed will be added.

Bump, would appreciate any assistance whatsoever. I don't know how to figure out what's causing it.

I had disabled it after getting the BSODs with it enabled. It's still currently disabled, and I don't get the BSOD anymore, but the computer still self reboots.

I just had a bizarre and surprising occurrence.

I formatted a thumb drive with Memtest86+ and rebooted with the drive plugged in, but it didn't boot into the test. I went into my bios settings and changed the thumb drive to boot first, saved and reset, but it still didn't boot into the test. I entered the bios settings again, moved it around in boot order then put it back to the first spot to see if that may jog it. Then, when I saved the changes and reset the computer this time, it made its initial boot noises for a moment, then shut down entirely. I wasn't sure what happened; when saving and exiting from the bios, it always reboots and never simply shuts down, so I thought maybe I had done something wrong.

Then it started up again a few seconds later, just like the problem that led me to start this thread.

I don't know if that's significant to what may be the problem. I don't want to say that I don't think it's a PSU problem, but I've had this PSU for over a year, and I've never had any problems with it before. I haven't added any hardware since quite a while before these problems began. But that doesn't rule it out, does it? :/
Also, I don't have another PSU to test with.

Otherwise, I ran Furmark for 5 minutes; temperature capped at 78C and no artifacts appeared. The system did not reboot; it seemed pretty stable. Should I let it run for longer? It has taken about 5-10 minutes for my computer to shut down while gaming after rebooting from it happening before.
I ran Prime95 for 30 minutes with no errors and no problems. CPU temps capped at 81C. If I need to run these for longer, let me know; I'm pretty new to benching/stressing.
Honestly, stressing my GPU and CPU was quite frightening at first; I've never seen the temps nor the fans' RPMs go that high before for any reason, haha.

I'm not sure why my computer won't boot to the Memtest86+ thumb drive; is there a way to force it?

How do I get Windows to create a .dmp file when the computer crashes? When I try to get it to do that, it says that the pagefile is disabled or less than 1 MB, despite the fact that I have it set to system managed size and it has 8159 MB.

I feel like a .dmp file when the computer crashes like it has been would be very helpful, but that's the only type of dump file I know of and I don't know how to get it to work properly.

Set the Hard Drive first to boot in BIOS setup (unless UEFI) then trigger boot media using the one-time BIOS Boot menu key only.

Please post back a screenshot of Disk Management - Post a Screen Capture Image
so we can look over your configuration, check that the Active partition is correct.

Then run a few Startup Repairs to see if they find anything to repair.

What exactly are you using to "clean my machine?" Registry cleaners and other optimizing suites are death to Win7. You might as well start over and stick with the steps, tools and methods to get and keep a perfect Clean Reinstall - Factory OEM Windows 7 - same for retail. The tutorial compiles everything that's worked best here since beta, in tens of thousands of installs we've directly helped with.

I used the regular Memtest86 (not the + version) and it ran overnight and it returned 0 errors: https://i.imgur.com/7Ug8QZ2.jpg

I can't seem to find a way to get the recovery options to do startup repair... the available options screen when pressing F8 during post doesn't seem to have startup recovery.

I've used CCleaner and Auslogics Boostspeed, but it's been a while since I used those. I'm leaving a clean reinstall as a last resort, but if it gets down to it, I'll do it.

Computer management screenshot is attached.