Another method - since it is going because another program is using it, then stop the other program!
Even if you don't know what it is, do a 3-finger salute. Start at the bottom of the list. Write the name down and stop it. Then see if you can delete it. If not, repeat.
You write these down because if you stop a critical file, Windows will crash (duh)! Then you can reboot and know not to stop that program from running.
I do like booting into DOS and doing it that way, and get the file attributes first, or just clear all of them. If the file is in a directory maybe you can give the directory a new name! When it reboots it won't be there! Ha, ha! Gottcha!
Also check to see that your autoexec.bat file hasn't been changed to include that program in your start-up. Check your start-up menu too.
Glenn