randomly freezing up

hey all,

i have a 1.6 Ghz pentium wioth 256 MB ram

windows xp pro originally

computer will randomly freeze up. screen stays static ctrl+alt_del doest work. when i reboot event logs tell nothing

I reloaded the box from scratch with windows 2k3 for a project i am doing and the problem returned

I have updated the OS with all patches.

i have all nbewest drivers for all hardware.

its really bugging me.

the problem doesnt happen while i am on the computer only after some period of inactivity.

i hvae reloaded several times with different OS’s and different options but hardware remains same. I hvae reseated cards all to no avail.

HELP!