My PC is rebooting by it self ?!??

[Guest]

Hi;
My PC (ATHLON XP 2600+; Win XP PRO OS) is rebooting by it self after
selecting the “Turn Off†command (similar to “Restart†selection). I have to
push the main switch to OFF on my Pwr. Center before it starts to reboot
again.
This problem started only recently and I do not know why.
I restored the critical system files to earlier date - NO change. (
Is any one familiar with this kind of problem/ fix ???
Please let me know.
Thank you; Bill

 

[Guest]

99.9% of the time when a computer restarts itself instead of shutting down
is caused by a hardware issue.Try removing a recent install,or remove 1 at
a time if not sure.

 

[Guest]

Thank you Andrew for your reply.
I am running a dual OS on this PC with two selectable Hard drives.
With the Win 98 SE the PC "Turns Off" OK; this should exclude the hardware
problem (?). I reinstalled/repaired the Win XP OS with NO help. MB BIOS is OK
(?) since the Win 98 function OK....
There is a segment in the registry or in the Boot /Sht Dn system which is
instructing the machine to REBOOT or to Turn Off, which may be mixed up; I
just do not know where it is... (