Faulty RAM or "agressive BIOS settings"?

This was all I could find out about my rig with my limited knowledge on computers-
System: Microsoft Windows XP Pro (5.1, 2600)
Processor: Mobile AMD Anthlon(tm) XP-M Processor 2800+, ~1.6GHz
Memory: 1024MB of RAM
Video Car: NVIDIA GeForce4 MX 4000
Hard Drive: 80GB WD Caviar
Model # (I think): M817G

I'm hoping thats good enough specs

This was my original question-
Like the description says, my computer randomly freezes on me and I have no idea why. I happens 9 times out of 10 when I'm playing a game (any game), but on those rare 1 out of 10 times its when I have Winamp, Mozilla, or any other program open. My first idea was that it was a software problem so I had my computer completely reformatted, but it still freezes. By freezing, I mean just that. As a more in depth description everything, no matter what I'm doing, stops mid stride. I can't move the mouse, can't open anything up, (if I'm playing a game) nothing on my character moves, music cuts off, and I can't even go to the desktop or do the whole "Crtl+Alt+Delete" thing either. Its just frozen in place and all I can do is manually restart it by either flipping the power swith in the back or by pressing the restart button upfront. My next idea was to get a new mother board but, frankly, I don't have the money right now. I don't get online with that comp, so I know it's not spyware or a virus, and I've even updated to the most recent driver for my videocard. So if anyone... ANYONE at all has any insight as to what might be going on I would Greatly appreciate it.

This is the updated version of my question-
I recently came to the conculusion that my comp's RAM isn't doing to hot so I believe it's what is causing my computer to freeze so often as it does. I ran MemTest, the RAM reliability tester, and it came up with close to 80 Memory Error Detections. When I went to the FAQ for MemTest it said "Your RAM is bad, or your system is incorrectly configured. If you have overclocked your machine, or selected aggressive RAM timings in your BIOS you should try more conservative settings before judging the ram fully bad."
I just remembered as well, my sister and I have Identical, down to the very last part, computers. My bro's made them for us. And I went digging around and found out that she has her BIOS on "Default System BIOS", as do I, and her comp runs damn near perfect which leads me to believe, even more so, that I have a faulty stick of RAM.
So my question is, should I just flat out junk my RAM and get a new one or is there a simple way that one, such as myself, could check to make sure the BIOS settings aren't to high? Thank you for any suggestions whatsoever!