Non Static vs Static

[steve65]

I must admit I am still trying to determine the best way of using statics. I have the following code:

using System;
using System.Windows.Forms;

namespace WindowsApplication1
{
	internal class Class1
	{
		internal Class1(){}

		internal static void Main()
		{
			Class2.TestString = "";
		}
	}
}

using System;
using System.Windows.Forms;

namespace WindowsApplication1
{
	public class Class2
	{
		string myTestString = null;

		public string TestString
		{
			get {return myTestString;}
			set {myTestString = value;}
		}
	}
}

When I try to run the code I get: An object reference is required for the nonstatic field, method, or property 'WindowsApplication1.Class2.TestString' at the line Class2.TestString = "";

If I change Class2 and the TestString property to a static I am able to compile the code. In VB I was able to add properties to any of my public classes without any problems.

I can use static but I am not sure why I should and why it worked and what repercussions it has on my code. Would somebody be able to explain this to me?