Hard drives spinup after being idle

I've noticed Windows XP and Windows 7 doing this.. anyone know the reason? I've got 5 hard drives plugged in. Before going to bed i'll be browsing the net, so only my C drive will be active (temp files, etc).. the other spin down.

I've noticed that when I decide to go to bed, about 5-10 minutes after having not touched the computer, at least one of my other hard-drives spin up. I have defrag scheduling disabled, I don't run any antivirus, and nothing else I have does any sort of idle work. It has to be something in Windows directly.. the question is, why does it spin up the other drives?

Anyone else noticed this?

right click on taskbar and run start task manager. Go to performance tab and then click the resource monitor button. Click on the disk tab and youl be able to see what is accessing your drives and take any action necessary.

I think your power options turn off your hard drives after a certain amount of time idle

Don't know about XP, but both W7 and Vista start doing some maintenance/tweak stuff like defrag/rearrange after a while the comp has been idle.

For example, this is just a part of the things that start in W7 (no idea which use HDs a lot):

AnalyzeSystem, This job analyzes the system looking for conditions that may cause high energy use, Idle for 5mins
AitAgent,, Idle for 3mins
Autochk, This task collects and uploads autochk SQM data if opted-in to the Microsoft Customer Experience Improvement Program, Idle for 10mins
CrawlStartPages, Index all crawl type start addresses, Idle
Defrag, This task defragments the computers hard disk drives, Idle for 3mins
ProgramDataUpdater,, Idle for 3mins
SR, This task creates regular system protection points, Idle for 10mins
VerifiedPublisherCertStoreCheck, Inspects the AppID certificate cache for invalid or revoked certificates, Idle for 3mins
WinSAT, Measures a system's performance and capabilities, Idle for 10mins

WINDOWS DEFENDER apparently is set to run at 2AM daily. That was another thing I just found that would cause my hard drives to spin up

Theres likely to be a number of automated tasks, some of which can be rescheduled.

Are you sure it is not doing something connected with Indexing ?

I've also got 5 HD's connected here, i dont think i've seen this problem, but i'll check, usually i turn off automatic things like defender/updates/scheduler and i think indexing is off too.

If i need something i'll tell it to do it but yeah, i havnt noticed this.

if you have 5 hds then you could move indexing over to another hd and thatl reduce the hogging of windows drive. likewise relocate the pagefile to another drive.