Pocket KillBox is a program that can be used to get rid of files that stubbornly refuse to allow you to delete them.

Usage Information:

Download this file, extract it, and run the killbox.exe file. When it loads type the full path to the file you would like to delete in the field and press the Delete File button (looks like a red circle with a white X). It will prompt you to reboot, allow it to do so, and hopefully your file will now be deleted.