You cannot set the startup form from any toolbox in C#. instead you will have to instantiate that form in the Main method. Here is a snippet that ususally lies in
Program.cs
. Just instantiate the form you want to run on startup instead of
form1
.
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}