There's no feeling in computing quite like when you're trying to delete a file to fix a problem but can't because the file is open and won't close because of the very same problem you're trying to fix. Help is available in the form of KillBox, a small program that attempts to terminate and delete open and running files.
KillBox is portable freeware, meaning you can park the downloaded program file where you like and run it with a click. Also known as Pocket KillBox, this is indeed a compact program, at 90 KB, with an equally compact interface with an entry field for entering file locations or browsing for files, a button to display file properties, and a delete button. Check boxes let us select Standard File Kill, Delete on Reboot, and Replace on Reboot, that last offering a handy option to substitute a dummy file. We could also opt to end the Explorer shell and unregister .dlls. Two buttons let us select whether to kill a single file or all the files in the path. Since we didn't have an unresponsive file to unleash KillBox on, we created a duplicate image file, opened it in Photoshop, and then browsed to the file's location with KillBox. We pressed the program's red X icon, and, after some pop-ups telling us what was going on, KillBox deleted the file, which we verified, though the image still remained open in Photoshop. However, the deleted file wasn't in the Recycle Bin; it was in the KillBox folder, waiting to be autopsied. KillBox creates a log file of operations, which can be handy for such postmortems. KillBox's interface also has an expandable Processes window for selecting system processes to terminate. Options included removing duplicates and directories and forced shutdown and reboot.
If you've never had to terminate or delete a file to fix a problem, you will, sooner or later. When you do, you'll be glad to have KillBox in your toolkit.