C#检测系统是否激活[转自StackOverFlow]

using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;

namespace ConsoleApplication11{
using SLID = Guid; //SLID id declarated as typedef GUID SLID; in slpublic.h

class Program
{

public enum SL_GENUINE_STATE
{
SL_GEN_STATE_IS_GENUINE = 0,
SL_GEN_STATE_INVALID_LICENSE = 1,
SL_GEN_STATE_TAMPERED = 2,
SL_GEN_STATE_LAST = 3
}

[DllImportAttribute("Slwga.dll", EntryPoint = "SLIsGenuineLocal", CharSet = CharSet.None, ExactSpelling = false, SetLastError = false, PreserveSig = true, CallingConvention = CallingConvention.Winapi, BestFitMapping = false, ThrowOnUnmappableChar = false)]
[PreserveSigAttribute()]
internal static extern uint SLIsGenuineLocal(ref SLID slid, [In, Out] ref SL_GENUINE_STATE genuineState, IntPtr val3);

public static bool IsGenuineWindows()
{
bool _IsGenuineWindows = false;
Guid ApplicationID = new Guid("55c92734-d682-4d71-983e-d6ec3f16059f"); //Application ID GUID http://technet.microsoft.com/en-us/library/dd772270.aspx
SLID windowsSlid = (Guid)ApplicationID;
try
{
SL_GENUINE_STATE genuineState = SL_GENUINE_STATE.SL_GEN_STATE_LAST;
uint ResultInt = SLIsGenuineLocal(ref windowsSlid, ref genuineState, IntPtr.Zero);
if (ResultInt == 0)
{
_IsGenuineWindows = (genuineState == SL_GENUINE_STATE.SL_GEN_STATE_IS_GENUINE);
}
else
{
Console.WriteLine("Error getting information {0}", ResultInt.ToString());
}

}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
return _IsGenuineWindows;
}

static void Main(string[] args)
{
if (Environment.OSVersion.Version.Major >= 6) //Version 6 can be Windows Vista, Windows Server 2008, or Windows 7
{
if (IsGenuineWindows())
{
Console.WriteLine("Original Windows");
}
else
{
Console.WriteLine("Not Original Windows");
}
}
else
{
Console.WriteLine("OS Not supoprted");
}
Console.ReadLine();
}
}}