Static classes must derive from object (C#)

I am having a problem in C#, the output states:

Error   1   Static class 'WindowsFormsApplication1.Hello2' 
cannot derive from type 'System.Windows.Forms.Form'. Static classes 
must derive from object.

How could I correct this?

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();

        }

        private void button1_Click(object sender, EventArgs e)
        {
             Hello2.calculate();
        }
    }



    public class Hello : Form
    {
        public string test { get; set; }

    }


    public static class Hello2 : Form
    {
        public static void calculate()
        {
            Process.Start("test.exe");

        }
    }