Have you ever tried to delete a file in Windows only to be greeted with the message that it cannot be deleted because it is being used by another person or program?
I think that if the OS is informing you about an attempt to delete a file that has a handler open, it should be smart enough to tell you one thing: which is the application/process using it.
While there is no workaround for this problem, there is a utility that can help you find the offending process that is not letting go of that file. Unlocker is a (free) utility that will give you this info. Once installed, it is a contextual menu:
Unlocker will then present you with a dialog that will let you deal with the situation: