i have recently done a clean install of xp pro on my pc which has an amd athlon 600 processor, 256 mb ram and ibm deskstar 25gp hard drive. All was working fine under win98se and no problems reported during the compatability test before install. Since the install though if i leave the pc alone for more than 3 mins the system seems to go to sleep! If i click on something or press a key i can hear the hard drive whirr up and then the system responds. It even happens during the download of a largish file from the internet or even during the typing of a decent size Word doc! its really annoying and i cant think how to correct it. There are no new drivers for the HDD and i have checked to see if any of the hibernation or power schemes are enabled and they are not - anyone any ideas, i'm pulling my last 4 hairs out!!

if you have checked the power schemes already the other other place i can think of is the BIOS as some machines have secondary settings in there.