Go to Control Panel\System and Maintenance\System, on the left-hand side,
select Advanced System Settings. Accept any prompts from UAC. Under
Startup and Recovery, click Settings, then uncheck the box 'Automatically
restart' under System Failure.
Now your pc will give you a BSOD blue screen instead of rebooting. Make a
note of the exact error code. This will help determine what is causing the
reboots. There may even be a reference on the blue screen to a driver.
--
Jane, not plain

64 bit enabled :-)
Batteries not included. Braincell on vacation ;-)
"Vista-Man" <Vista-Man@discussions.microsoft.com> wrote in message
news:83B57D6F-8AD4-404C-8001-7B4A518D85DC@microsoft.com...
> Upon completion of a clean installation of Windows Vista Home Premium
> (64-bit), my system started to reboot on its own. It happens randomly.
> The
> hardware was previously running Windows 2000 Professional and never had
> this
> problem. I have a 750 Watt powersupply and the temperatures always are
> reasonable when I check in the bios.
> Has anyone else had this problem? What could be the cause and or the
> solution?