I dont know why, but now, when I turn off my computer, the CPU fan does not turn off. The only way to fully turn it off is from the back.I dont know what could be wrong.Could it be the fan or the cpu?Also, sometimes, when i turn it on it sounds like (not sure) that it keeps restarting (without actually loading anything), then it finally loads upI took virtually every part out (Power fan, CPU fan, CPU, RAM, CD Drives, Hard Drives, and Floppy drive) then put them back in, did not help

The fan can be broken. Or the BIOS can have a setting that if it above a temperature it would say on until it is cool.