So, after a lengthy day of some C# battles, a few Exchange issues, and some ded.pixel blaring through the speakers, I went to clean-up some folders from my desktop. I received the dreaded 'Folder In Use' message from Windows:

Alright. That's odd. All that's in there is two csv files. Excel isn't open. So, needless to say, I have no readily apparent signifier as to what's got this folder on lock-down.

Enter handle. Handle is your friend, in these times of need.

O.k., Outlook. Why do you have a handle on the folder? Took a dump of the process of Outlook, closed it, and the file could then delete.

It's up to the Outlook EEs to figure out why Outlook kept a handle on that file, now.