OK. I am back. I have a friend's PC that I am trying to figure out. I have unplugged the floppy, zip drive, modem, CD-Rom and ethernet card. When I turn on the PC it boots up and it jumps into a blue screen with some type of error exception that gives a memory address. I did see the letters "VXD" on the same page. I hit OK and the same blue screen comes back a few more times. It finally goes back to the main screen and the PC then locks up. Since I unplugged all the stuff above, I have narrowed it down to the operating system , power supply, mother board, processor or hard drive. I already know the mother board has a bad memory slot and am thinking that it is probably going bad. I believe it is a Amptron mother board that has the video, audio, and ethernet built in. Before I go out an get a new MB,CPU,HD, anything I should try to make sure? Thanks.