If you have a look at Win32::KillProcess you will see some Perl code that lets you connect to remote machines and do whatever you have perms for. Probably the easiest way is to sutdown and reboot the remote machine which will force a logoff by default. I don't know why you would actually want to logon to a machine you are not sitting in front of. You can manipulate them without doing that per se.

The Microsoft Windows 2000 Resource Kit and Microsoft Windows NT Resource Kit supply a shutdown.exe utility that you can use to shut down or reboot the local or a remote machine. I'm sure you can find it on the web ;-) This utility also lets you configure how to handle hung applications. For example:

C:\> shutdown \\morpheus /r /t:15 "Astalavista Baby"
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