I got the following code to run the application at windows startup:
private void SetStartup(string AppName, bool enable) { string runKey = \"
Have you tried
this.WindowState = FormWindowState.Minimized;
If you want to start minimized at windows startup only you can add extra argument to command line, like myapp.exe --start-minimized, then you can parse this parameter and detect whether you need to start minimized or not.
myapp.exe --start-minimized