WIN:XP Reboots

When I click on turn of computer windows says it is shutting down
and then re-boots without turning off. Duriing this process NO Blue screen ever appears indicating there was a problem causing windows to restart.

New install of XP no other programs installed, motherboard is SOYO: SY-7VDA and have flashed bios with latest bios update (2002). Have also UNCHECKED restart in System advanced set-up.
Have also checked power management in bios setup for correct settings. Motherboard is new unit. For the heck of it I did install Win:98se to see how unit works and shut-down was okay. Then FDISK'd and formatted hard drive NTFS and re-installed XP AND back to same old re-boot problem when I tell wiindows to shut down.
Should also mention there is NO cd-writter installed...
Thanks fer listening......Dennis

 

Don't double post Dennis!