Interop.cs

using System;
using System.Runtime.InteropServices;
using System.Security.Principal;

namespace RegSave
{
    public class Interop
    {
        [DllImport("advapi32.dll", CharSet = CharSet.Auto)]
        public static extern int RegOpenKeyEx(
            UIntPtr hKey,
            string subKey,
            int ulOptions,
            int samDesired,
            out UIntPtr hkResult
        );

        [DllImport("advapi32", SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        public static extern bool OpenProcessToken(
            IntPtr ProcessHandle,
            TokenAccessLevels DesiredAccess,
            out IntPtr TokenHandle
        );

        [DllImport("advapi32.dll", SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        public static extern bool AdjustTokenPrivileges(
            IntPtr TokenHandle,
            [MarshalAs(UnmanagedType.Bool)] bool DisableAllPrivileges,
            ref TOKEN_PRIVILEGES NewState,
            uint BufferLength,
            out TOKEN_PRIVILEGES PreviousState,
            out uint ReturnLength
        );

        [DllImport("advapi32.dll", SetLastError = true)]
        public static extern bool LookupPrivilegeValue(
            string lpSystemName,
            string lpName,
            out LUID lpLuid
        );

        [DllImport("advapi32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
        public static extern int RegSaveKey(
            UIntPtr hKey,
            string lpFile,
            IntPtr lpSecurityAttributes
        );

        [DllImport("advapi32.dll", SetLastError = true)]
        public static extern int RegCloseKey(
            UIntPtr hKey
        );

        #region structs
        [StructLayout(LayoutKind.Sequential)]
        public struct LUID
        {
            public uint LowPart;
            public int HighPart;
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct TOKEN_PRIVILEGES
        {
            public uint PrivilegeCount;
            public LUID Luid;
            public uint Attributes;
        }
        #endregion
    }
}