My computer keeps freezing randomly and I don't know why, it is windows 7(fresh install), it has OCZ 2 2gig rams, anthelon x2, msi motherboard, and a 9800 gtx+ geforce graphics card. I have also tried to download the latest driver but it still freezes.(Not a pre-made computer)

First I would try a different operating system to rule out Windows 7 as it is still fairly new and could cause issues. You can download e.g. ubuntu linux live cd and run it off the cd to see if your system still freezes. If it does then indeed you might have a hardware problem. Live CD usually contains memory test programs, you could try running that to check the RAM.
Have a look in the BIOS-it might be worth resetting the settings to default/failsafe settings.
If you still can't find any issues I would suggest opening the PC and checking for obvious overheating. Make sure all fans are spinning (check the one on the video card too) and remove any dust if necessary.
If all is in order, try swapping the video card (or removing it in case you have onboard one).
I hope you sort it out, it sounds like a nice system :)
Good luck,
Raf