This would perform a somewhat similar task as winpopup does.
1. Goto command prompt (to do this, click on the start menu and select run, then type in cmd)
2. Type net send * (your message)
Note: the * would send the message to all of the computeres in the same workgroup as you. To send the message to a specific computer, type in the computer's ip address.
Send a message to everyone in your workgroup
Posted in Windows XP by Community Submission