Identifying the process or user that has a lock on a folder or file

In Windows Server 2008, it was easy to identify the user that had a lock on a folder or file. As a last resort, you could always log off that user to release a lock.

In Windows Server 2012 R2, as far as my limited understanding, it is more difficult to identify which user or process has a lock on a folder or file. Is there a MS or third party technique or tool to achieve this?

I looked at the third party tool called Unlocker, but I think that that does not work on network drives.

Many thanks.

Keith

R K Howard