Question: I have a strange problem: Every half hour one of my hard disks gets powered on again. I recognize this by the sound of a hard disk spinning up.

So far I was not able to track which program could cause this.

  • I ran Process Monitor to see whether there is an I/O peak coinciding with the spin-up.
  • I checked Windows event viewer if there is an appropriate event at the same time

Any ideas other than the usual disabling-services/programs etc. (which would be my next investigation step)?

Also, it would be helpful to have a program that shows the current power status of all my drives, if there is one. Harddisk Sentinel unfortunately cannot do the job because it powers on all drives upon start and prevents their going into sleep mode.

Answer: On technet sysinternals you can find Process Monitor. It can see all the file open or access commands that can cause disk spin up. The downside is that under normal circumstances it collects a lot of information so finding the misbehaving application will be tricky.

If you don’t want to access those drives at all, a better option would be to “unmount” the partition. You can do that by unassigning drive letter in Disk Management. Then regular applications shouldn’t be able to cause a spin up.