Follow the steps:-
1) First set the ShowInTaskbar property of form to false,
2) After add NotifyIcon control on the form,
3) Now first set the icon property of notifyicon to a proper icon,
4) After that set its visible property to false,
private void frmNotify_Resize(object sender, EventArgs e)
notifyIcon1.Visible = true;
6) After this add a ContextMenuStrip and create a toolstrip for show and in its click event write
this.WindowState = FormWindowState.Normal;
7) Now in property of notifyicon you can find a property for contextmenustrip now add the object of contextmenustrip.
8) That's it run you're code and minimize it you can find it on your task bar now right click it and click on show.
Hope this will solve your problem.