Hello Phillip_Hermes, most likely Norton is stuck scanning that file and has it locked while doing so.
With your keyboard press Ctrl+Alt+Delete keys at the same time. In the screen that appears click Task Manager. When that opens make sure you are viewing the “processes” tab. Scroll down and find the Microsoft Office Click-to-run run process. Or Word.exe. Right click on the one you can locate and in the menu select “terminate process”. That should close Office and the file that is open.