Freezing issue, please help

Are you able to borrow a power supply and test that with your system? I'm assuming it could be the cause of your problems.

A difficult problem. usually i RAM is the culprit it causes a BSOD freeze/crash. It's possible it's the power supply but my guess would be a software issue possibly hard drive related.

software gets tricky. My advice unfortunately is to do a FULL reinstallation (FULL NTFS) of Windows. The "FULL" part is important is it reads and writes to build up a bad sector table.

Troubleshooting:
Do things in order of what is the easiest and/or cheapest. this is NOT in order as I don't know if you can get access to parts
1) replace PSU
2) reinstall Windows
3) swap RAM or troubleshoot by using HALF of your RAM at a time (Memtest is good but not 100%)
4) replace graphics card (very doubtful it's the problem)
5) remove the hard drive completely and run from a Linux Live CD (such as Ubuntu). The advantage is that if it's a hard drive physical problem of software issue this can prove it. The disadvantage is mainly in how long the glitch takes to occur.

You can try try JUST the software by going to the Ubuntu page and installing WUBI which will download and install Ubuntu 9.04 x64 as default. It installs like a program so add/remove gets rid of it but to enter you REBOOT and select Ubuntu so it in no way is linked to Windows when in use. You can use Firefox, OpenOffice easily.

Basically you need to swap out hardware or software to troubleshoot. It can be a pain I know but look at it as a learning experience.

QUICK FIX:
There is something you can try that MAY help. Go into your device manager and right-click and remove any PATA or SATA controllers. REBOOT. Everything will auto install but there are bizarre glitches in XP, Vista and Windows 7 that happen. This fix is also used for inexplicable Read and/or Write speeds being slow. I've fixed MANY computers with this (even recently with Windows 7 RC). Anyway, this can't hurt anything and I recommend ANYBODY just go ahead and do it.

manually set everything in the bios - ram to 1:1 ratio and voltage to ~1.9v (more depending on what the default of the ram is) - see how it goes

bios's think they know best - they do not.

Thanks for the suggestions so far! Really appreciate it. I'm currently trying out mike99's suggestion.

Last night, I tried removing my sata devices one by one to see if that made a difference. Froze each time.
However, I plugged those devices back in and my computer hasn't froze yet today.
Anyway...
- I don't have replacement psu; if it comes down to it, I'll try to test my psu on a friend's system
- gonna avoid reinstalling windows until the end, after testing hardware
- I'll get a replacement graphics card and test my system

Note: I never had a bsod before. The screen would just freeze; mouse, keyboard, and speaker would become unresponsive.