There is an option in my application to hide the window - **form.hide()**, and to put an notifyicon in the system tray, and when you click the notifyicon there will be a form.show().

If someone will try to run two instances of the app, I want 
a. not to run the new instance
b. to show the window of the first instance

I already have a loop to check if a process with the same name exists.
and I can tell the new app not to run ( **return** in the program.cs before `Application.run(new form())`)

but I yet have to tell the first app to show its main window.

I have the process (of the first instance) , i can get its handle its id etc.

the question
How to show the window using it's process?