Computer Freeze - Need Advice

[UnSeEn]

Hey all! Haven't been on here in ages...but when the old computer acts up, I know who to call :)

Okay, here's the scenario: I was having some CPU overheating issues a couple of weeks ago - turns out the fan A) wasn't mounted particularly well and B) the heatsink was clogged with dust. I benched my computer, dusted it out, put the fan back in. Major improvement! Temps were idling at around 35C or so, and I was happy. I decided, while I was at it, to wipe my hard drive and install Windows 7 instead, which I've heard is much better than Vista.

Did that, and not 20 minutes after installation, my computer froze. As in, no activity, no mouse, nothing. A complete freeze. I restarted the computer. In 5-10 minutes, the same thing happened. I tried reinstalling Windows, but the same freeze occurred during the installation. I wiped Windows completely and tried on a different hard drive, but same issue. So here's where I am now:

- It's not a hard drive issue, as 2/2 drives suffer the same issue.
- It's not a video card issue, as I've tried switching from my GeForce 9800 GTX to my GeForce 6800 GS, and though the computer is stable a little longer with the older card, it still eventually fails.
- It's not my CPU, or at least, it's not an overheating issue, as temps stay pretty much nominal.
- It's not a RAM issue, as I've tried switching out each stick accordingly to no avail.

Ultimately, it's gotta be either the mobo or the power supply, but, having no replacement parts, I can't test any of these theories.

So, hardwareforums.com, what do you think? Are there any tests I can do to see which is the broken piece of hardware? I would hate to go out and buy a new PSU, only to have it be a mobo issue, as I have not the money to spend on such things...help!

Specs:
Gigabyte mobo (more details if necessary)
Intel Dual-Core 2.8ghz CPU
GeForce 9800 GTX
2 gigs DDR2 ram
500w power supply

 

[Sniper]

Hi UnSeEn, hope all is well!

Have you tried Vista (again) instead of Windows 7?

 

[UnSeEn]

Hey Sniper, long time no see! All IS quite well, thanks for asking. And you?

And no, I haven't tried Vista since I installed Windows 7 the first time. Then again, I suspect this isn't a software issue, since now I don't have a Windows of any kind installed and the issue still occurs. For example, I'll boot from my Windows 7 disk, leave it idling for 10 minutes, and it'll still freeze, regardless of the lack of an active OS. Ack...

 

[Sniper]

All good, thanks.

Looks like you've already tried quite a few things dude! Did you try different memory sticks or just alternated between existing ones? I guess you could consider running Memtest86+ - Advanced Memory Diagnostic Tool overnight to see if you get any errors, assuming it stays stable for more than 10 minutes.

 

[UnSeEn]

I alternated between my two existing strips of memory and the issue still occurred. And oh how I wish I could run the computer long enough to run Memtest86+...however, at this point, I can't even run it stable enough to install an OS, let alone test out diagnostics. Grraarrggh!