Need to know how to create registry key at setup installation in Windows application

i need to create registry key while installing my setup file. what i have to do....
Actually i created the installer class with the below code.

using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Configuration.Install;
using System.Linq;


namespace StockManagement
{
    [RunInstaller(true)]
    public partial class Installer1 : Installer
    {
        public Installer1()
        {
            InitializeComponent();
        }
        public override void Install(System.Collections.IDictionary stateSaver)
        {
            base.Install(stateSaver);
            int count = 10;
            Microsoft.Win32.RegistryKey key = Microsoft.Win32.Registry.LocalMachine.CreateSubKey(@"SOFTWARE\WIN32");
            key.SetValue("Sys", count, Microsoft.Win32.RegistryValueKind.String);
        }
    }
}

then i build it...
and i add it in my setup file under
custom actions-->install\

after build my setup file
when i install in my system it creates the registry key...
and works normally..
but when i install in other systems during installation.. i got the error

ERROR:1001 Unable to get the installer types in the c:\program files\stock management.exe assembly.--> Unable to load one are more of the requested types: Retrieve the loader exception property for more information..

how to solve this error...

Tags: .NET (.NET 3.5), Windows, Application, Setup, Registry