|It could be one of many things. If you have 2 sticks of ram, remove 1, then try it. If it still freezes then put it back in and try the 2nd ram and see if it still freezes up.|
If you get it NOT to freeze up, order another stick of ram.
Try blowing out the fans with compressed air, it may be heating up.
If it's not the above, it could be the hard drive is failing.
Some HELP in posting on Computing.net plus free progs and instructions Cheers