I want to make a Backup program, and the problem is that it cannot backup if the file is in use. So obviously I have to close the program that is using that file, but I don't know how to find out what program is using it... If I could, then I could programatically close the program and start the code that back's up that file...

And by the way, don't tell me "just look for yourself" or something like that, cuz I can't. The backup program should run at 12:00 AM, and I'll be home when that hapens, not at work, where the backup is done.

Anyone has any ideas ?