How can you pop up a message or run a program on remote computer so the currently logged on user can see it.
We have done this on WinXP, but these don't work with Win7.
at.exe \\computername time /interactive message.vbs
(time is hh:mm at least a minute in the future)
psexec.exe \\computername -I message.vbs
To test it you could replace message.vbs with Notepad.exe