Random BSOD

If it's not crashing it doesn't need to be on.
Also, it'll unecessarily complicate things if left on - please turn it off.

Since you ran verifier according to my instructions, then it's most likely that there's not a problem with 3rd party drivers. That leaves hardware problems as the next most likely (and I suspect the video card from a previous post). Please do the following:

I suggest starting all troubleshooting with the following diagnostic tests. They'll save you a lot of time and heartache if there is a hardware failure, and you'll have the disks on hand in case you need them in the future:

H/W Diagnostics:
Please start by running these bootable hardware diagnostics:
Memory Diagnostics (read the details at the link)
HD Diagnostic (read the details at the link) - Test ALL of the hard drives.

Also, please run one of these free, independent online malware scans to ensure that your current protection hasn't been compromised: Free Online AntiMalware Resources (read the details at the link)
There are also free, bootable antivirus disks at this link: Free Online AntiMalware Resources - Bootable Disks

Then, if the above tests pass, I'd try these free stress tests:

FurMark download site: FurMark: VGA Stress Test, Graphics Card and GPU Stability Test, Burn-in Test, OpenGL Benchmark and GPU Temperature | oZone3D.Net
FurMark Setup:
- If you have more than one GPU, select Multi-GPU during setup
- In the Run mode box, select "Stability Test" and "Log GPU Temperature"
Click "Go" to start the test
- Run the test until the GPU temperature maxes out - or until you start having problems (whichever comes first).
NOTE: Set the alarm to go off at 90ºC. Then watch the system from that point on. If the system doesn't display a temperature, watch it constantly and turn it off at the first sign of video problems. DO NOT leave it it unmonitored, it can DAMAGE your video card!!!
If the temperature gets above 105ºC, quit the test - the video card is overheating.
- Click "Quit" to exit

Prime95 download site: Free Software - GIMPS
Prime95 Setup:
- extract the contents of the zip file to a location of your choice
- double click on the executable file
- select "Just stress testing"
- select the "Blend" test. If you've already run MemTest overnight please run the "Small FFTs" test instead. (run all 3 if you find a problem and note how long it takes to error out with each)
- "Number of torture test threads to run" should equal the number of CPU's times 2 (if you're using hyperthreading).
The easiest way to figure this out is to go to Task Manager...Performance tab - and see the number of boxes under CPU Usage History
Then run the test for 6 to 24 hours - or until you get errors (whichever comes first).
This won't necessarily crash the system - but check the output in the test window for errors.
The Test selection box and the stress.txt file describes what components that the program stresses.
More details on the use of this test: Torture test your CPU with Prime95

More Video Stress Tests:
1. Thanks to VirGnarus for finding this test: https://simtk.org/home/memtest
2. Two other video stress tests (may be more stressful than FurMark):
NOTE: I have had reports that some ISP's will block this website
Video Memory stress Test - http://nvworld.ru/utilities/vmt/
Artifact Locator - http://nvworld.ru/utilities/alocator/
Sorry, but I don't read the language that this website is made in.
3. Another interesting test that came to my attention: Download - OCCT Website english
USE AT YOUR OWN RISK - the program doesn't have a whole bunch of safety features to protect you from yourself!

CPU Stress Tests:
- http://downloadcenter.intel.com/Deta...19182&lang=eng
- 7Byte : Hot CPU Tester Pro
- 7Byte : BurnIn64
- CPU Stress test - Overclock.net - Overclocking.net
- Fossil Free Online CPU Load or Stress Test.
- CPU Stability Test description, System Resources Tune-Up. Downloads List By All Time Popularity | PCWorld | PCWorld
- CPU Stress test - Overclock.net - Overclocking.net
- |MG| CPU Stability Test 6.0 Download
- LinX - A simple Linpack interface

BSOD BUGCHECK SUMMARY

Code:

Loading Dump File [C:\Users\FUBAR\_jcgriff2_\dbug\__Kernel__\082111-35178-01.dmp]
Built by: 7601.17640.amd64fre.win7sp1_gdr.110622-1506
Debug session time: Sun Aug 21 10:09:57.863 2011 (UTC - 4:00)
System Uptime: 0 days 2:09:43.706
Probably caused by : ntkrnlmp.exe ( nt!ObpCloseHandleTableEntry+3e )
DEFAULT_BUCKET_ID:  VISTA_DRIVER_FAULT
BUGCHECK_STR:  0x50
PROCESS_NAME:  chrome.exe
FAILURE_BUCKET_ID:  X64_0x50_nt!ObpCloseHandleTableEntry+3e
Bugcheck code 00000050
Arguments fffff8a0`0a163d18 00000000`00000000 fffff800`04d78ebe 00000000`00000002
BiosVersion = P1.90
BiosReleaseDate = 07/04/2011
CPUID:        "Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz"
MaxSpeed:     3300
CurrentSpeed: 3292
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨``
Loading Dump File [C:\Users\FUBAR\_jcgriff2_\dbug\__Kernel__\082111-13509-01.dmp]
Built by: 7601.17640.amd64fre.win7sp1_gdr.110622-1506
Debug session time: Sun Aug 21 04:49:27.530 2011 (UTC - 4:00)
System Uptime: 0 days 0:25:21.747
BugCheck D1, {fffffa800d658090, 2, 0, fffff88000dd583f}
Probably caused by : ataport.SYS ( ataport!IdePortTickHandler+f )
DEFAULT_BUCKET_ID:  VISTA_DRIVER_FAULT
BUGCHECK_STR:  0xD1
PROCESS_NAME:  System
FAILURE_BUCKET_ID:  X64_0xD1_ataport!IdePortTickHandler+f
Bugcheck code 000000D1
Arguments fffffa80`0d658090 00000000`00000002 00000000`00000000 fffff880`00dd583f
BiosVersion = P1.90
BiosReleaseDate = 07/04/2011
CPUID:        "Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz"
MaxSpeed:     3300
CurrentSpeed: 3292
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨``
  
  

Disconnect the CD-ROM (both cables) and see if that stops the BSOD's
Disconnect the cable that goes from the mobo to the CD-ROM drive from the mobo also.

If you are using some sort of cleaning tool on your system, please don't use it while we're troubleshooting - it removes needed files.

Video was emitting a weird sound,

This isn't normal behavior. Did your speakers emit the sound, or was it coming directly from the video card? I'd either try more video stress tests, or try another video card. I've had experience with an OEM nVidia card that reported normal temps - but burnt my fingers when I was poking around in the case. That's where I learned the house fan trick (but it's not appropriate for you at this time).

We're looking for clues here, and the weird sound is the only strange thing that we've found. We've also seen video problems in the BSOD's - so the video card is the most likely problem.

BSOD BUGCHECK SUMMARY

Code:

Loading Dump File [C:\Users\FUBAR\_jcgriff2_\dbug\__Kernel__\082511-22198-01.dmp]
Built by: 7601.17640.amd64fre.win7sp1_gdr.110622-1506
Debug session time: Thu Aug 25 16:20:08.488 2011 (UTC - 4:00)
System Uptime: 0 days 4:54:14.705
Probably caused by : memory_corruption ( nt!MiBadShareCount+4c )
BUGCHECK_STR:  0x4E_99
DEFAULT_BUCKET_ID:  VISTA_DRIVER_FAULT
PROCESS_NAME:  svchost.exe
FAILURE_BUCKET_ID:  X64_0x4E_99_nt!MiBadShareCount+4c
Bugcheck code 0000004E
Arguments 00000000`00000099 00000000`000cdfc9 00000000`00000002 00000000`000cdfc5
BiosVersion = P1.90
BiosReleaseDate = 07/04/2011
CPUID:        "Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz"
MaxSpeed:     3300
CurrentSpeed: 3292
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨``
  
  

Not a problem with the minidumps - it's just that I often see extra minidumps that the poster hasn't noticed, so I check the older one's to ensure that I've run everything.

I've heard screeching from video cards before - most often from the fan. What this usually means to me is that there is a problem with the fan - and that it may stay running for a while and then seize up intermittently (causing the card to overheat). Also, if the card screeches, it's not normal - so the card is to blame.

If you're technically able to repair the fan and cooler, give that a try. Otherwise it's time to try another video card.

Yep, the VMT test found a pile of errors. Interestingly, it didin't find them in every resolution that it tested.
It'd be interesting to run the test several times to comparer results (to see if the resolutions that tested OK will stay OD).

So, it's time to try a new video card - BUT - purchase one that you can return for a refund, just in case this isn't the actual problem. It's most likely that this is the video card, but other problems can occasionally cause test failures.

Good luck!