How can I kill a process from the command prompt on Windows NT?

If you had XP or later you could use TASKKILL. This on not NT though.

I think you're going to have to download something to do this. I'd recommend pskill from Sysinternals.

You can use this either with a process ID or just with a process name. For example:

pskill notepad.exe

Another option is KILL from the NT Resource Kit.