I have a Dell Deminsion 8400 that’s about 18 months old. Recently, the PC started to freeze for no apparent reason. This is a classic freeze…i.e., no BSD, just a pure freeze with no KB or Mouse input accepted…all running sw, even winamp, stops. There’s no Dr. Watson log file saved. I’ve scanned the PC for viruses etc. and haven’t added any software or hardware recently. All the drivers are up to date. I also cleaned the dust out of the MB, PS, Fans, etc... What are the recommended diagnostic steps to track this problem down?