//目前程式目錄
string ApplicationBase = System.AppDomain.CurrentDomain.SetupInformation.ApplicationBase;
//Windows目錄
string winDir = System.Environment.GetEnvironmentVariable("windir");
//桌面目錄
string folder = Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory);

 
// 系統特殊目錄
// Environment.SpecialFolder
Desktop: C:\Documents and Settings\Administrator\桌面
Programs: C:\Documents and Settings\Administrator\「開始」功能表\程式集
Personal: D:\My Documents
Favorites: C:\Documents and Settings\Administrator\Favorites
Startup: C:\Documents and Settings\Administrator\「開始」功能表\程式集\啟動
Recent: C:\Documents and Settings\Administrator\Recent
SendTo: C:\Documents and Settings\Administrator\SendTo
StartMenu: C:\Documents and Settings\Administrator\「開始」功能表
MyMusic: D:\My Documents\My Music
DesktopDirectory: C:\Documents and Settings\Administrator\桌面

MyComputer:
Templates: C:\Documents and Settings\Administrator\Templates
ApplicationData: C:\Documents and Settings\Administrator\Application Data
LocalApplicationData: C:\Documents and Settings\Administrator\Local Settings\Application Data
InternetCache: C:\Documents and Settings\Administrator\Local Settings\Temporary Internet
Files Cookies: C:\Documents and Settings\Administrator\Cookies
History: C:\Documents and Settings\Administrator\Local Settings\History
CommonApplicationData: C:\Documents and Settings\All Users\Application Data
System: C:\WINDOWS\system32
ProgramFiles: C:\Program Files
MyPictures: D:\My Documents\My Pictures
CommonProgramFiles: C:\Program Files\Common Files

// 環境變數 //
Environment.GetEnvironmentVariable("環境變數名稱")
OS: Windows_NT
WINDIR: C:\WINDOWS
USERPROFILE: C:\Documents and Settings\Administrator
TEMP: C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp

// 暫存目錄
Path.GetTempPath(): C:\Documents and Settings\Administrator\Local Settings\Temp\