Most server administrators separate their content from their system data (at least I think they do :) ). Content that grows will from time-to-time get by the monitoring process and bring a server to a halt because there is insufficient space on the sytem drive to continue.
As I built up another test server image I had a desire to delete the c:\wmpub\wmiislog folder which Windows Media Services leaves behind. From explorer you can't delete this folder because it is in use. But what is using it? After a quick search with Sysinternals Process Explorer I found that winlogon.exe is the culprit.
But why? A search of the internet has revealed no published rational behind this. Being a fan of keeping things in order there doesn't appear to be any purpose behind the folder so I'm nuking it. To make this happen I first had to close the handle using Process Explorer (right click on the handle, “Close Handle”) and then remove the folder.
The bad news is that upon reboot the folder reappeared. Hopefully we'll see this change in the next release of Windows Server.