Standby & Monitor

[Guest liques]

When ever I leave my computer for a while it seems like it has gone into

standby, but when I move the mouse to wake it up it has actually shut down

and as soon as the screen wakes up windows xp starts up again as if it has

been restarted. This has only started since i wiped my comp and reloaded xp

from scratch. I have got xp back up to date with all the updates. Anyone

help??