How to Detect 64bit OS/Process on .NET 2.0 to 3.5

Introduction

Simple function to detect:

• Operation System is 64 bit?
• Process is 64bit?

The Code

    using System;
    using System.Diagnostics;
    using System.Runtime.InteropServices;

    public static class Misc
    {
        [DllImport("kernel32.dll", SetLastError = true, CallingConvention = CallingConvention.Winapi)]
        [return: MarshalAs(UnmanagedType.Bool)]
        public static extern bool IsWow64Process([In] IntPtr hProcess, [Out] out bool lpSystemInfo);

        /// <summary>
        /// Detect Operation System is 64bit
        /// </summary>
        /// <returns></returns>
        public static bool Is64BitOS()
        {
            using (Process p = Process.GetCurrentProcess())
            {
                bool retVal;
                return (IntPtr.Size == 8 ||
                        (IsWow64Process != null && IntPtr.Size == 4 && 
                         IsWow64Process(p.Handle, out retVal) && retVal)
                       );
            }
        }

        /// <summary>
        /// Detect Process is 64bit
        /// </summary>
        /// <returns></returns>
        public static bool Is64BitProc()
        {
            return (IntPtr.Size == 8);
        }
    }

How to Use

if(Misc.Is64BitOS())
{
    Console.WriteLine("Os is 64bit");
}
else
{
    Console.WriteLinve("Os is not 64bit"); // means 32bit at 2015-02-03 :)
}

if(Misc.Is64BitProc())
{
    Console.WriteLine("Process is 64bit");
}

Notes

IntPtr.Size is 8 in 64bit Process and 4 in 32bit Process.

"WOW64 is the x86 emulator that allows 32-bit Windows-based applications to run seamlessly on 64-bit Windows."
IsWow64Process detects 32bit process runs in Wow64.

.NET 4, and .NET 4.5

System.Environment.Is64BitOperatingSystem for checking OS

System.Environment.Is64BitProcess for checking Process