This is a simple example for Windows Form Application. I programmed it to display a small form in the center of the screen like this.
Which makes it look like a updater of sorts for a corporation which if you click on the install button it uses a loop to redisplay a message box like this.
I used the simple infinite loop:
{
}
A warning to you that is an infinite loop meaning if you run that in any thing but the C# debugger you'll have to close it by Pressing and holding Ctrl. + Alt. + Delete, and when the Task Manager shows up, you select the process called NPDR Corp.exe and end it.
I recommend reading Head First C#