1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.IO;
 6 using Microsoft.Win32;
 7 using System.Diagnostics;
 8 using System.Runtime.InteropServices;
 9 
10 namespace AppGet {
11     class Program {
12         static void Main(string[] args) {
13             Register();
14 
15             Console.WriteLine("press any key to exit.");
16             Console.ReadLine();
17         }
18 
19         private static void Register() {
20             RegistryKey systemPathKey = Registry.LocalMachine.OpenSubKey(@"SYSTEM\CurrentControlSet\Control\Session Manager\Environment", true);
21 
22             if (string.IsNullOrEmpty(systemPathKey.GetValue("AppGet", string.Empty).ToString())) {
23                 systemPathKey.SetValue("AppGet", Path.GetDirectoryName(Process.GetCurrentProcess().MainModule.FileName), RegistryValueKind.String);
24             }
25 
26             string path = systemPathKey.GetValue("Path", "Empty", RegistryValueOptions.DoNotExpandEnvironmentNames).ToString();
27             if (!path.ToLower().Contains(@"%appget%")) {
28                 systemPathKey.SetValue("Path", @"%AppGet%;" + path, RegistryValueKind.ExpandString);
29             }
30 
31             int rtnVal = 0;
32             SendMessageTimeoutA(HWND_BROADCAST, WM_SETTINGCHANGE, 0, "Environment", 2, 5000, rtnVal);
33         }
34 
35         private const int HWND_BROADCAST = 0xffff;
36         private const int WM_WININICHANGE = 0x001a, WM_SETTINGCHANGE = WM_WININICHANGE, INI_INTL = 1;
37         [DllImport("user32.dll")]
38         private static extern int SendMessageTimeoutA(int hWnd, uint wMsg, uint wParam, string lParam, int fuFlags, int uTimeout, int lpdwResult);
39     }
40 }