Make the Program Runs When I Press A Button in Another Program

[Atran]

Hello:
I have two programs (Windows Forms).
I want to make the second program runs when I press a button in the first program.

So when the user go to run the second program, I want the second program doesn't run.
But if the user go to run the second from the first program, I want the second
program runs.
Thanks for anyhelp.

[Plater]

Use the process object from the first program.
Make the 2nd program require some kind of special command line argument to run?

[Atran]

Use the process object from the first program.
Make the 2nd program require some kind of special command line argument to run?

Thanks for your idea.