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Cmd help
Well, both taskkill and tskill work on my machine… dunno why the first one wouldn't work on yours. As for doing that remotely, it's just a command… gain remote access to a machine's command prompt (running Windows XP or later, of course) and you should be able to run that command (if you have elevated privileges). I'm sure plenty of the articles detail how to gain remote access to a Windows PC.