You could try a program called Screen Popup 3.00. We use it on our Windows 7 PCs, and it also works on Windows XP.
It looks nicer than net send - can be a little fiddly to setup, but once it's working it's a dream.
http://www.softpedia.com/get/Internet/Chat/LAN-Messaging-Clients/Screen-Popup.shtml
It's freeware so no cost.
We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.