LockHunter is a free 64/32 bit tool to delete files blocked by any processes
http://lockhunter.com/-- Shared with Google Share Button
There are several file unlocker tools for Windows. In the past, I've used Unlocker as well as FileAssassin, the latter of which is made by the great Malwarebytes organization.
I was unhappy with FileAssassin because it didn't feature explorer integration. Unlocker was good but always felt a little off to me, and even though it seemed to work it always seemed a bit Windows-98ish to me and I wanted something better.
I'm currently trying LockHunter and we'll see how it fits the bill.