PC Locks up when idle

hello all, i have a 1.5 gig machine with an intel 845 motherboard and 528mg ram

lately its been locking up on me, usually when its idle. the power saving settings are all off.

when heavy processing is going on ( ie, games ect) i have no problems.

its always a hard freeze too, cant get to task manager cant get caps light on ect, always have to reset.

it started around the time i added a 2nd harddrive. i’ve made sure that the ide drivers are all the most current. the only other thing that has changed is that MS media player has been loaded and i cant get rid of it as you know.

there does seem to be a hesitation or delay when accessing that 2nd drive, gut feeling tells me its something with this but not sure.

might it benefit me to get a memory defrag type software or that norton software to try to stop the hard freezes.