Executing a software, remotely ,using the udp protocol?

Hi

I wrote 2 Win applications that can communicate with each other through the udp protocol.I would like to launch one of them(D:/Unity/myUnity1.exe) by sending a command from another application running on a different computer. How can I do this? I think the desire code will open the command prompt and execute the application in the specified stored address.

Well you have to write this application. This functionality definetly is not implemented in any secure operating system.
Here is the solution to starting a program: https://msdn.microsoft.com/en-us/library/system.diagnostics.process.start(v=vs.110).aspx
Problem is that this application then needs to be executed in background all the time.

A different way that would be possible is to just keep the program you want to start running in background and let it listen for an incoming packet indicating the real startup of it, ie. loading assets into memory and initializing the scene.