freezing screen, Crash

I have just about had it with this one.The pc freezes every now and then, even just after I log on. Sometimes later. I cannot install a new Game I got called : Madde Man, as it keeps asking for a file called IMM.exe. Not sure if both problems are related though. I have took my sound card out, used all sort of programs to see if the pc has a virus or trojans, and still it freezes.
Any help mwould be really appreciatted. Thank you.

Specs.
AMD Socket 754 MB
AMD Sempron Proc 2800

RAM 1 Gig
200 Gig Maxtor HD

Nvidia 6800 Graphics card
Onboard sound PowerMax

Freezing is generally a hardware problem.

Often heat related but could also be a failing power supply or even failing hard drive.

Is the computer old? Have you cleaned it recently? Checked the fans? Reseated the RAM and Graphics card?

You can get a PSU tester and you can also run a diagnostic on your hard drive. The manufacturer's web site will have one to download.

Thanks Jephree. It would appear it is now stopping me from opening pages on the net from links. I did reseat the Ram. Opened the caes for a spel to give it a bit of air. But I think today I shall reinstall the lot ans see again if it is the system. I shall try another hard drive as well, perhaps. It is a brand new PSU 580 watt.Hyper. I will take the G/card out and do a clean o it as well. I will let you know later how it went.
Cheers again.