Unlocker - Unlock your locked files
Windows is not particularly friendly with resources and there are many programs that don’t release them. Files get stuck with programs and when you want to delete them Windows throws up an ugly message which looks something like this.

“Cannot Delete XYZ-File: The files are being used by the following program: Program Name. You must close the file before proceeding”
You know that you don’t have the file open, but according to Windows, you do. That’s where this handy little utility called unlocker comes in. It isn’t guaranteed to work all the time, but most of the time it will get you out of the jam, or at the least tell you what it is that’s holding Windows back from operating on the file/folder.
When such an error message pops up, Unlocker brings up this dialog which allows you to do a couple of things. You could take no action, copy the file, delete the file or unlock the file. You could also kill the process that currently is holding the file.

I’ve run in to problems many times myself and have had this utility save me. One more good tool to add to the tool chest.