Sometimes we encounter locking of media files by servers like WMS or IIS.
They provided access to file at some point, but long after usage, the file is still locked for deletion, and only restart of server WMS or IIS process helps.
Unfortunately, there isn't a silver built solution for all use cases, but here is nice conversation on that topic for WMS by Neil Smith:
with this article from Microsoft:
How To Improve Server Performance when Streaming On-Demand Content from a Remote Share
explaining how to control WMS file open share mode.
