If you receive File in Use. The action can't be completed because the file is open in another program even if file is closed in another program, see this.

How to delete a file being used by another program Here are some practical ways to dodge the pop-up and delete files that are in use by a program on your Windows PC.

Cannot rename file on Desktop? File Name too long? Action cannot be completed because the file is open in another program? Access is denied in OneDrive? Here's the fix!

But not all files are locked by Windows processes, some files could be locked due to a malware. With Unlocker, you will only be able to kill the malware process, but cannot delete it.