Unlocker solves the problem of locked files in Windows. If you get the message “Cannot delete… It is being used by another person or program” then Unlocker can unlock the file for you and let you delete it just by right-clicking the file and choosing “Unlocker”.
I found this utility to be very useful, but you must always use such utilities with care – in this case only when you are certain that no program is using the file you are about to delete.