User License

I have developed an application.
Now I want to distribute this product as trialware.

The feature I want is that if a copy of my product is already present in a network then the new copy which has been installed should not work.

Can this be done if yes can u help me.

Regards.
Vivek

A way you can do this is to have a winsock control and send a UDP message containing the computer name. if you receive a message that is not your name then you kill the app. if you do this every couple of seconds then one of the apps will die.