Random crashes - help please

[Templisk]

Hey guys, I'm having some random crashes. These occur most often while playing video games but occasional when the computer is left idle I come back to a crash.

While playing a game everything will be functioning as it should, then my sounds will stutter and die. At the same time I get a message saying no video input detected as if I just unplugged it from the video card. The computer stays on with the fans running but I am unable to preform any key presses nor can I hear anything going on (example: Ventrilo chatter just stops)

Possibly related issue: If I watch YouTube videos in HD and then fullscreen them my audio gets distorted then stops entirely until I close and reopen the browser.

I currently have:
CPU: Intel Core 2 duo E8400 @ 3.0ghz (planning an i5-2500k upgrade I know I'm bottle necked)
CPU Cooler: Arctic Cooling Freezer 7 Pro
GPU: XFX GeForce GTX 295
Sound card: Creative Soundblaster X-Fi Xtreme Music
Mobo: EVGA nForce 750i
PSU: Antec 850W
Memory: 4gb (2x2gb) OCZ Platinum DDR2 1066
HDD1: Velociraptor 300gb
HDD2: WD Caviar 500gb (nothing at all is on or run from this drive yet though it is connected)
OS: Windows 7 Home Premium 64bit
Case: Thermaltake armor with an additional 120mm fan added to the front via a HDD cage.
Peripherals: Logitech G-19 keyboard, Logitech G9x mouse, Sennheiser PC-350 headset

Troubleshooting steps taken so far: Reformatted computer with a fresh install of Windows 7. Ran full windows update, installed anti-virus (webroot internet security), ran virus scan, installed latest drivers for motherboard, sound and video cards. Issues continued so took apart the computer, made sure everything was clear of dust and if it wasn't I used an electronic safe air duster and then performed the above steps a second time. Additionally for the youtube video issue someone recommended disabling hardware acceleration on the flash videos after it continued when changing browsers from chrome to firefox and back.

I would greatly appreciate any tips I have no idea where to start on this.

 

[Templisk]

Update: ran Prime95 for 3 hours today and never went over 55C or crashed.

 

[lewza]

It sounds as if your machine is overheating, therefore, crashing itself as it cant cope.

Another thing you may want to try is checking event viewer see if anything has gone down as a log file.

 

[AdrianPerry]

Downloading "HWMonitor" is a good way to keep an eye on all your temps.

It almost sounds like your PSU is topping out, but at 850w and Antec being a solid manufacturer, i don't see how it possibly can be.

Is your motherboard properly fastened down to your case using the correct stand-off screws ect? It could be shorting out which is causing interference followed by a crash.

 

[lewza]

If it shorts out from the case mate it would probably make the motherboard faulty.

 

[Templisk]

I checked the event log there's only 1 critical error but it repeats itself over and over.

Event 41, Kernel-Power The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly.

The rig has been the same for the last 2 years the only change I've made is switching an 8800 GTS for the GTX 295 and it ran fine up until a few months ago. I do regular driver and windows updates so I'm wondering if it might be a faulty driver. Last night I disabled my Soundblaster card and ran onboard sounds and still crashed so I can rule out the sound card I think.

I don't think I'm maxing out on the PSU, everything that could possibly draw power is included in my original post and the G19 keyboard has it's own power supply that attaches to the wall so power use through the USB port would be minimal. Could the PSU be going out maybe?

When I put the computer together I used the included screws - the goldish colored ones that raise the motherboard off the case and then the silver screws to secure the motherboard into the other ones.

I ran Prime95 again for 10 minutes (until my temps didn't get any higher for 2-3 minutes) and this is what I got:

 

[Templisk]

Issue is still ongoing, any ideas to try to resolve this?

 

[Templisk]

Update: ran memtest for a little over an hour with no failures going to try an all night test tonight to make sure I'm good to go. Also ran Prime95 for 8 hours last night with no errors and temperatures comparable to the last screenshot.

However I did find a pattern in my event viewer:
Critical errors: Event 41, Kernel-Power The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly.

Errors: Event 6008, EventLog The previous system shutdown at 2:52:49 PM on ‎9/‎21/‎2011 was unexpected.

and
Warnings: Event 219, Kernel-PnP The driver \Driver\WUDFRd failed to load for the device Root\SIDESHOW\0001.

all have the same time stamps so I think I've narrowed it down to that driver. Only problem is that even with the Logitech keyboard my drivers are up to date. I'm going crazy going in circles here.