using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Win32;
using System.Deployment;

namespace RegisteryCheck
{
    class Program
    {
        static void Main(string[] args)
        {
            ApplicationDeployment ab = new 

            

        }
    }
}

Please could you tell me exactly what you are aiming to do?

Also are you sure you havent got an error
here

ApplicationDeployment ab = new

doesnt it need to be

ApplicationDeployment ab = new ApplicationDeployment

Try using the namespace System.Deployment.Application; instead of
using System.Deployment;

using System.Deployment.Application;

I agree with saravind84. using System.Deployment.Application should work.