How do you kill a process by name for all users?

Run taskkill /im process.exe /f /t as Administrator.

If you include that command in a .bat file (batch script), you can run the .bat file as an Administrator by:

1. Create a shortcut for the .bat file
2. Right-click the shortcut and select properties
3. In the shortcut tab select "Advanced"
4. Select "Run as administrator" and click OK

Your command is correct. But you need to open a cmd as administrator first. Open Start, find Command Prompt, right click, open as administrator.

taskkill /im process.exe /f /t