Open CMD or PowerShell as administrator.
taskkill /?
Review the options.
tasklist
To see the running tasks. What I found interesting is that I had a bunch of winword.exe running. If I did:
taskill winword.exe
It would give me an error and say it couldn’t find winword.exe
However, if I did it by filtering by the user, it worked:
taskkill /F /T /IM winword.exe /FI "USERNAME eq username"