Before I get into anything specific, I've got to say that this has been happening for at least a year and a half, so I've done nearly everything I can think of to try and fix it. Reinstalls, reformats, various drivers, etc. I've looked for answers on other boards, but nothing has been able to fix the problem.
The issue: my computer will, randomly, freeze. If I have sound playing, the speakers will continue to play the last sound forever. There is nothing specific I can do to cause the issue. It doesn't happen everyday, but there are times it happens once or twice a day. I used to assume that a driver was causing it, as it tended to freeze while I was playing games, but that was because I actually played games at the time. It has frozen (that I can remember) while playing FFXI, LotRO, Champions Online, using Visual Studio, most often while some sort of Flash is running, and most recently whenever I moused over the Start bar (I have it auto-hide; the bar popped up and it froze). Until the last freeze, it had never happened without some sort of Flash running or game being played (which was the reason I'm posting this; a new cause might get me some new help). I don't recall the computer ever freezing while I played Oblivion or Age of Empires, but I can't be sure of that.
The latest freeze broke my most recently theory, which was that there was something wrong with the soundcard. In all of the cases before, there had been some sort of sound playing (but it didn't always keep playing sound; I never figured out why). I'm still convinced that it is a hardware issue and not a software issue, because the computer doesn't crash, it just freezes. The OS doesn't do a memory dump, I don't get a BSOD, and the event viewer shows no problems before the freeze, just the usual error after it reboots (Unexpected shutdown).
Hardware:
Asus P5N32-E SLI nForce 680i
Intel Core 2 Extreme Q6850 @ 3.00GHz
2x Corsair DDR2-800 1024MB
Creative Lab Sound Blaster Audigy SE
nVidia GeForce 8800GTX 768MB
Western Digital 500 GB 7200RPM [16MB cache, iirc]
Microsoft Windows Vista Home Premium 32-bit and Windows 7 64-bit
1000 watt Power Supply
I've done hardware diagnostics on each piece, with all of them coming back with no errors. The only thing I'm not certain about is the power supply. The last time I took it apart, I didn't trust myself to mess with too much (I just make sure everything was connected properly, since I didn't build this PC). I forgot to check the PS then and I haven't had time to tear it down since then. I know that the case came with a 420 watt PS and my math says that the components in this would need at least a 600 watt PS (which is why I bought the 1000 watt one). I don't know much about diagnosing power supply issues, but from what I do know power supply issues usually present themselves as over-heating and random reboots, not freezes.
Temperature (in-case someone suggests it might be overheating, I've never had the temperature readings up when it freezes and I don't know the proper ranges, so I can't be sure):
GPU: 65C (normal range)
Fan: 4000RPM
CPU: 54-60C or 46C (might be an issue with the program I'm using, because only one fan is listed as running when I can see three are spinning).
Internal Temp: 45C
Room Temp: 23C
Since I'm going to be taking it apart to make sure it isn't as simple as a lose connection, as soon as I find my laptop, any suggestions are appreciated, be it software or hardware.
XI Wiki

