Thanks for the input Mark, but I have a question to follow up on this. Are you saying that the video driver can cause a complete lockup of the OS? In other words, not just the video stopping, but all other functions as well. This seems to be the case in my situation. Actually, all I can say is that the keyboard is frozen too, but can't say about other processes necessarily. I have seen situations before where the console was locked up, but the OS kept running providing, in my case, dialup RAS service. I could log onto my computer remotely, but not at the keyboard. This was for another machine entirely, however. Peter -----Original Message----- I have never seen freezes caused by bad memory. When you have bad memory you get either failure at POST, or spontaneous reboots in windows. With modern motherboards, overheating a CPU, will result in a automatic shutdown, not a freeze. With a freeze, the first thing I would suspect is the video driver, or video card, or something related to it. Video cards, and drivers, cause freezes. First I would try new video drivers. If that didn't help I would put a new video card in ...any old PCI card would do. If the problem disappears then think about a video card replacement. But if the problem is still there, start thinking about the motherboard... maybe try more conservative BIOS timing settings, moving PCI cards around, remove cards one at a time and see if the problem goes away. Rode Do you want to signoff PCBUILD or just change to Digest mode - visit our web site: http://freepctech.com/pcbuild.shtml