My grandson downloaded an old DOS freeware game (Titans of Steel).

It consists of only one file... TosInst.exe

When I try to delete the file, I get a message...
Error Deleting File or folder
Cannot Delete TosInst.exe It is being used by another person or
program.
Close any programs that might be using the file and try again.

I cannot locate any program or user (I'm the only user) that is using this
file. Nothing in Task Manager, and nothing indicated in "Starter", an
application I have that displays all apps initiated at Startup.

How can I force this file to delete?

Thanks for your help,
Al Camp