reboot problems

[Guest]

i having problems. i have athlon 800 with shuttle mother board. out of the blue the computer reboots itself. thought it was the board but replaced that and still doing it. can it be the harddrive or operating system. i am totally lost can use any help available

 

[AMD_cErTiFiEd]

what videocard are u using
I have seen this problem a few times before
detail your hardware and configuration