Yep. Windows along with some antivirus, indexing, and defrag engines will try to work during idle time to clean up/scan your system.

Wait till you try Vista! It amazes me how much hard drive activity goes on during idle time on my laptop compared to XP (of course maybe it has to do with the fact that this is an upgraded OS).

When I am at home I set my laptop to Always On (when it was XP) and now High Performance in Vista. Either way I made sure the only thing that shut down was the monitor during idle time.

On the road I set it so the display blanks after 5 minutes and the system hibernates after 10 minutes.

>I am pretty sure that it is Windows that is the culprit
>Windows does many things during "HD idle time". 2 that I know of are:
>- updates it 'fast search' database;
>- periodically, performs a DEFRAGMENTATION (yes, it absolutely DOES).
>There are probably many more... search for updates come to mind.
>
>cheers