I'm not sure what is causing this my computer has been freezing continuously for three days. It will freeze during any part of loading, when its idle, trying to run the format disk, or looking at the bios. At one point it said unmountable_boot_drive but I ran my recovery disk and that went away. Also ran my virus scan several times always coming up clean along with running my pc doctor program that says everything passed with no problems. It has windows xp and is a gateway system a few years old. Any suggestions greatly appreciated cause I can't run anything on it for long.