Process Explorer will show running processes but not open files.
OpenedFilesView is a freeware application that will display all open files and what processes opened them. It will also allow you to kill any of the current open files so they can be moved or deleted.
This utility works properly on Windows 2000/XP/2003/Vista (32-bit only !). Older versions of Windows (NT/9x/ME) are not supported. Also, you must have administrative privilege in order to run this utility.