My computer is Win2000 or WinXP that does not work properly, the same effect and restart each time. Turn off the ACPI power management in the BIOS to turn directly to the screen that can't be started to windows log. Ask you the heroes are the problem of Windows power management or the BIOS settings? Hardware has tried the same machine with a single machine, and there is no problem. The operating system reloads N times, which is not particularly changed by default settings. The motherboard is SIS 9XXX, can't be recognized, with the graphics card support 533 Overseofa P4, and now uses P42.0 400 outgoing. When the hardware is tested, there is only a different power supply. If there is a problem, the machine is a Micro ATX structure, and I don't know if Windows power management is required?