ubuntu 11.10 freezes

[Jon Anderson]

It does sound like you have a hardware problem of some sort.
Try using unity-2d, that gets rid of compiz and clever graphics stuff.
  At the logon screen click the wheel above the password and select 2d

Presumably there is nothing in the logs to indicate the cause of the
problem.  If not then I believe overheating is a possibility.

Perhaps a new machine or mother board would be the best plan. :(

Colin
  Ya I agree been looking for something I can afford and have to put a few dollars together to get it.