I have been troubleshooting an issue for a week where the p.c. goes through normal quick shutdown process but just restarts instead of shutting down.. It started after I clean installed 7100 on an old Gateway that had been running 7000 fine for 3 months. WHen it became impossible to fix I reverted to XP and it continues. Several search results mention audio, but I figure if it is audio or any other failure to terminate it would show in the Performance Events Log, which it doesn't. Also since shutdown starts straightaway from Start Menu or Power Button and then quickly moves to restart without pausing at all on the desktop, I figure it isn't a failure to terminate a service but something deeper in hardware or the bios, esp since it persists in the XP reinstall. So I set BIOS back to defaults and tested hardware. But it grows even more confounding when I did a HD diagnostics from bootable GWScan disk and then navigated to exit and the computer shut down instantly using power button from the boot mode, which seems to say the hardware is working fine. WTF?