Sorry for the dumb question in advance.

I have been trying to get Ubuntu to work on my machine for almost 2 months now. I've tried almost every Ubuntu-based distro out there and all of them freeze at completely random times.
When I managed to install it on my hard drive without it freezing mid-install it still froze constantly when using it. I've got no idea what the issue is or how to fix it but all I know is that the mouse doesn't move at all and ctrl+alt+f2 doesn't do anything while it's frozen.

I doubt it's my graphics card or CPU overheating because I can run them at very hot temperatures without any glitches or freezes on Windows.

If anyone could help me I would be extremely appreciative. This issue has been frustrating me for so long and I hate to join a forum just to ask for support but no one else seems to have this issue, and the Ubuntu community is known to be really helpful and nice compared to other Linux communities.

My hardware specs:

Graphics card: ATI Radeon HD 6970

CPU: AMD Phenom II X6 1090T

PSU: Thermaltake TR2-800AH2NFB

RAM: I'm not sure what kind of RAM I've got, however I do know that I have 4GB of it and I ran a memtest on it. It showed no problems with it at all.

Motherboard: ASUS M4A89GTD Pro

Again, I apologize for the extremely stupid question but I'm really desperate here. I'm loving Ubuntu on my laptop and I think I would love it even more on a fairly decent gaming PC instead of having to use Windows 7 to do things Ubuntu can do even better.