If it says it’s in use, check if it’s open. If it is, close it and then delete or try closing the program that you used to open the file because maybe the program hasn’t released it yet. Still there? Try renaming the file then deleting it after. This usually works with an AVI file.
If the above does not work, reboot your PC. Don’t open any other programs instead go to the file first then delete it before you open any programs.
If still not successful, download a free copy of MoveOnBoot. This is software that permits you to Move, Copy or even Delete a file before Windows locks or alters the file. Look for the problem-causing file and then delete it. You must reboot your PC ASAP, but if you’re doing something, it can wait. This will still run when you open your PC.
If it is still there, it might be a virus or spywares in your system. It is advisable that you have a good virus scanner or spyware removal and run those programs.

