WhoLockMe

Sometimes, the operating system may deny a simple operation such as deleting a file. Though it may seem like it is no longer in use some running process could still hold it hostage.
WhoLockMe is a simple extension that becomes available in the context menu of files and folders and which can be used to reveal the processes currently locking the item you want to delete or move to a different location.

Simple installation process

You do not have to go through an installation per se, although there is a simple procedure to be followed, available in a plain text file in the downloaded archive.
With the fresh “WhoLockMe” entry in the context menu, you can check the processes locking a specific file and thus preventing its elimination from the current position. Apart from listing the lockers the application also provides the means to release the file.
As such, it offers the possibility to close a selected handle or to terminate the entire process with no greater effort than a mouse click.

A word of caution

Everything is quite simple, but keep in mind that closing a handle of a running program could bring with it unwanted events and a better approach would be to kill the process, after making sure that files depending on it have been saved.
In the list of items responsible of locking a file even after closing it, there are several details that may help you with better identification of the program it belongs to. The panel shows both the full path of the opened file and the location of the locking process.

Conclusion

WhoLockMe has not been updated in a while and it may not work on some operating systems, especially newer ones. It also includes the possibility to close handles, which may be a bit on the reckless side. All in all, there are alternatives that are under active development and that can achieve the same results, under safer conditions.