I had this problem for a period of time. It eventually went to blue-screen crashes.

My solution after some trouble-shooting was simple: I had two 1GB sticks of dual-channel RAM but I had failed to put them in the correct slots. Make sure they go in alternating slot sets for memory (as in put stick 1 in slot 1, but stick 2 in slot 3). Many motherboards require this setting for dual-channel memory.

fter I did that, I have not crashed or blue-screened since.