A friend has a new P4 with WinXP that does not want to switch off. It reboots after switching it off whether from within windows or by the power switch. Power supply was changed and still does the same. only by accedent I un plugged the CD Rom and it did switch off. The CD Rom is PERFECT and works well on another machine. What setting or adjustment is needed to MAKE this work with a CD rom.What do you mean switch off, shut down? The computer doesnt shut down instead it keeps restarting is that the question? The CD ROM should be fine when a computer keeps restarting it could be a heat issue or a hardware issue. Is the CD Drive near the CPU?Windows shuts down and immediately rebootes and starts up again. But it does shut down and stays down when the CD Rom is not connected. There is no heat issue. It happens when the computer is just started and the case is open. The Cd rom is FAR from the CPU and only by unplugging its power the system shuts down normally.Windows update. Quote

only by unplugging its power the system shuts down normally.