虽然是古老的问题，最近用到这个，查一下还不少东东呐
一、使用Environment.SpecialFolder
该方法最简单，直接使用即可，只是提供的特殊路径比较少。
(1)使用方法：
string path = Environment.GetFolderPath(Environment.SpecialFolder.Programs);
(2)获取参数：
foreach (Environment.SpecialFolder s in
Enum.GetValues(typeof(Environment.SpecialFolder)))
{
Console.WriteLine("{0} folder : {1}",
s, Environment.GetFolderPath(s));
}
(3)输出参数列表：
Desktop = C:\Documents and Settings\gmj\桌面
Programs = C:\Documents and Settings\gmj\「开始」菜单\程序
Personal = E:\我的文档
Personal = E:\我的文档
Favorites = C:\Documents and Settings\gmj\Favorites
Startup = C:\Documents and Settings\gmj\「开始」菜单\程序\启动
Recent = C:\Documents and Settings\gmj\Recent
SendTo = C:\Documents and Settings\gmj\SendTo
StartMenu = C:\Documents and Settings\gmj\「开始」菜单
MyMusic = E:\我的文档\My Music
DesktopDirectory = C:\Documents and Settings\gmj\桌面
MyComputer =
Templates = C:\Documents and Settings\gmj\Templates
ApplicationData = C:\Documents and Settings\gmj\Application Data
LocalApplicationData = C:\Documents and Settings\gmj\Local Settings\Application Data
InternetCache = C:\Documents and Settings\gmj\Local Settings\Temporary Internet Files
Cookies = C:\Documents and Settings\gmj\Cookies
History = C:\Documents and Settings\gmj\Local Settings\History
CommonApplicationData = C:\Documents and Settings\All Users\Application Data
System = C:\WINDOWS\system32
ProgramFiles = C:\Program Files
MyPictures = E:\我的文档\My Pictures
CommonProgramFiles = C:\Program Files\Common Files
合计：23行
二、使用Environment.GetEnvironmentVariable
该方法可提供更多内容。
(1)使用方法：
string path = Environment.GetEnvironmentVariable("ALLUSERSPROFILE");
(2)获取参数：
foreach (DictionaryEntry de in Environment.GetEnvironmentVariables())
{
Console.WriteLine(" {0} = {1}", de.Key, de.Value);
}
(3)输出参数列表：
Path = D:\Program Files\Sun\OPhone SDK\tools;D:\Program Files\Sun\android-sdk-windows-1.5_r2\tools;D:\Program
Files\Sun\SDK\jdk\bin;D:\Program Files\Sun\SDK\jdk\jre\bin;E:\oracle\ora92\bin;C:\Program Files\Oracle\jre\1.3.1\bin;C:\Program
Files\Oracle\jre\1.1.8\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\Program Files\Intel\DMIX;C:\Program
Files\Microsoft SQL Server\90\Tools\binn\;D:\Program Files\CodeSmith\v5.0\;D:\Program Files\Symantec\pcAnywhere\;C:\Program
Files\Ixia\IxChariot;D:\Program Files\Sun\SDK\bin;
TEMP = C:\DOCUME~1\gmj\LOCALS~1\Temp
SESSIONNAME = Console
PATHEXT = .COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH
USERDOMAIN = EVER62
PROCESSOR_ARCHITECTURE = x86
SystemDrive = C:
APPDATA = C:\Documents and Settings\gmj\Application Data
JSERV = E:\oracle\ora92/Apache/Jserv/conf
windir = C:\WINDOWS
_ACP_INCLUDE = D:\Program Files\Microsoft Visual Studio 8\VC\include;D:\Program Files\Microsoft Visual Studio 8
\VC\atlmfc\include;D:\Program Files\Microsoft Visual Studio 8\VC\PlatformSDK\include;D:\Program Files\Microsoft Visual Studio 8
\SDK\v2.0\include
TMP = C:\DOCUME~1\gmj\LOCALS~1\Temp
USERPROFILE = C:\Documents and Settings\gmj
ProgramFiles = C:\Program Files
FP_NO_HOST_CHECK = NO
HOMEPATH = \Documents and Settings\gmj
COMPUTERNAME = EVER62
_ACP_PATH = D:\Program Files\Microsoft Visual Studio 8\VC\bin;D:\Program Files\Microsoft Visual Studio 8
\VC\PlatformSDK\bin;D:\Program Files\Microsoft Visual Studio 8\Common7\Tools\bin;D:\Program Files\Microsoft Visual Studio 8
\Common7\tools;D:\Program Files\Microsoft Visual Studio 8\Common7\ide;C:\Program Files\HTML Help Workshop;D:\Program
Files\Microsoft Visual Studio 8\SDK\v2.0\bin;C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727;D:\Program Files\Microsoft Visual
Studio 8\;D:\Program Files\Microsoft Visual Studio 8\\SDK\v2.0\bin;C:\WINDOWS\SysWow64;D:\Program Files\Microsoft Visual Studio
8\Team Tools\Static Analysis Tools\FxCop\;D:\Program Files\Sun\OPhone SDK\tools;D:\Program Files\Sun\android-sdk-windows-1.5_r2
\tools;D:\Program Files\Sun\SDK\jdk\bin;D:\Program Files\Sun\SDK\jdk\jre\bin;E:\oracle\ora92\bin;C:\Program
Files\Oracle\jre\1.3.1\bin;C:\Program Files\Oracle\jre\1.1.8\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32
\Wbem;C:\Program Files\Intel\DMIX;C:\Program Files\Microsoft SQL Server\90\Tools\binn\;D:\Program Files\CodeSmith\v5.0
\;D:\Program Files\Symantec\pcAnywhere\;C:\Program Files\Ixia\IxChariot;D:\Program Files\Sun\SDK\bin;
USERNAME = gmj
NUMBER_OF_PROCESSORS = 2
PROCESSOR_IDENTIFIER = x86 Family 6 Model 23 Stepping 6, GenuineIntel
_ACP_LIB = D:\Program Files\Microsoft Visual Studio 8\VC\lib;D:\Program Files\Microsoft Visual Studio 8
\VC\atlmfc\lib;D:\Program Files\Microsoft Visual Studio 8\VC\atlmfc\lib\i386;D:\Program Files\Microsoft Visual Studio 8
\VC\PlatformSDK\lib;D:\Program Files\Microsoft Visual Studio 8\SDK\v2.0\lib;D:\Program Files\Microsoft Visual Studio 8
\;D:\Program Files\Microsoft Visual Studio 8\lib
WecVersionForRosebud.DA8 = 2
SystemRoot = C:\WINDOWS
ComSpec = C:\WINDOWS\system32\cmd.exe
LOGONSERVER = http://www.cnblogs.com/xinyuxin912/***
VS80COMNTOOLS = D:\Program Files\Microsoft Visual Studio 8\Common7\Tools\
_ACP_ATLPROV = D:\Program Files\Microsoft Visual Studio 8\VC\Bin\ATLProv.dll
WV_GATEWAY_CFG = E:\oracle\ora92\Apache\modplsql\cfg\wdbsvr.app
CommonProgramFiles = C:\Program Files\Common Files
PROCESSOR_LEVEL = 6
PROCESSOR_REVISION = 1706
CLIENTNAME = Console
ALLUSERSPROFILE = C:\Documents and Settings\All Users
VS90COMNTOOLS = D:\Program Files\Microsoft Visual Studio 9.0\Common7\Tools\
OS = Windows_NT
HOMEDRIVE = C:
合计：37行
三、调用shell32中的SHGetSpecialFolderPath
需要引用"System.Runtime.InteropServices”命名空间。
(1)使用方法：
[DllImport("shell32.dll")]
static extern bool SHGetSpecialFolderPath(IntPtr hwndOwner,[Out] StringBuilder lpszPath, int nFolder, bool fCreate);
const int CSIDL_PROGRAMS = 2; // \Windows\Start Menu\Programs
StringBuilder pathBuilder = new StringBuilder(260);
SHGetSpecialFolderPath(IntPtr.Zero, pathBuilder, CSIDL_PROGRAMS, false);
string path = pathBuilder.ToString(); // should now hold the path
(2)参数列表：
Here's the full list of CSIDL's from ShlObj.h
constint CSIDL_DESKTOP =0x0000; // <desktop>
constint CSIDL_INTERNET =0x0001; // Internet Explorer (icon on desktop)
constint CSIDL_PROGRAMS =0x0002; // Start Menu\Programs
constint CSIDL_CONTROLS =0x0003; // My Computer\Control Panel
constint CSIDL_PRINTERS =0x0004; // My Computer\Printers
constint CSIDL_PERSONAL =0x0005; // My Documents
constint CSIDL_FAVORITES =0x0006; // <user name>\Favorites
constint CSIDL_STARTUP =0x0007; // Start Menu\Programs\Startup
constint CSIDL_RECENT =0x0008; // <user name>\Recent
constint CSIDL_SENDTO =0x0009; // <user name>\SendTo
constint CSIDL_BITBUCKET =0x000a; // <desktop>\Recycle Bin
constint CSIDL_STARTMENU =0x000b; // <user name>\Start Menu
constint CSIDL_MYDOCUMENTS = CSIDL_PERSONAL;// Personal was just a silly name for My Documents
constint CSIDL_MYMUSIC =0x000d; // "My Music" folder
constint CSIDL_MYVIDEO =0x000e; // "My Videos" folder
constint CSIDL_DESKTOPDIRECTORY =0x0010; // <user name>\Desktop
constint CSIDL_DRIVES =0x0011; // My Computer
constint CSIDL_NETWORK =0x0012; // Network Neighborhood (My Network Places)
constint CSIDL_NETHOOD =0x0013; // <user name>\nethood
constint CSIDL_FONTS =0x0014; // windows\fonts
constint CSIDL_TEMPLATES =0x0015;
constint CSIDL_COMMON_STARTMENU =0x0016; // All Users\Start Menu
constint CSIDL_COMMON_PROGRAMS =0x0017; // All Users\Start Menu\Programs
constint CSIDL_COMMON_STARTUP =0x0018; // All Users\Startup
constint CSIDL_COMMON_DESKTOPDIRECTORY =0x0019; // All Users\Desktop
constint CSIDL_APPDATA =0x001a; // <user name>\Application Data
constint CSIDL_PRINTHOOD =0x001b; // <user name>\PrintHood
constint CSIDL_LOCAL_APPDATA =0x001c; // <user name>\Local Settings\Applicaiton Data (non roaming)
constint CSIDL_ALTSTARTUP =0x001d; // non localized startup
constint CSIDL_COMMON_ALTSTARTUP =0x001e; // non localized common startup
constint CSIDL_COMMON_FAVORITES =0x001f;
constint CSIDL_INTERNET_CACHE =0x0020;
constint CSIDL_COOKIES =0x0021;
constint CSIDL_HISTORY =0x0022;
constint CSIDL_COMMON_APPDATA =0x0023; // All Users\Application Data
constint CSIDL_WINDOWS =0x0024; // GetWindowsDirectory()
constint CSIDL_SYSTEM =0x0025; // GetSystemDirectory()
constint CSIDL_PROGRAM_FILES =0x0026; // C:\Program Files
constint CSIDL_MYPICTURES =0x0027; // C:\Program Files\My Pictures
constint CSIDL_PROFILE =0x0028; // USERPROFILE
constint CSIDL_SYSTEMX86 =0x0029; // x86 system directory on RISC
constint CSIDL_PROGRAM_FILESX86 =0x002a; // x86 C:\Program Files on RISC
constint CSIDL_PROGRAM_FILES_COMMON =0x002b; // C:\Program Files\Common
constint CSIDL_PROGRAM_FILES_COMMONX86 =0x002c; // x86 Program Files\Common on RISC
constint CSIDL_COMMON_TEMPLATES =0x002d; // All Users\Templates
constint CSIDL_COMMON_DOCUMENTS =0x002e; // All Users\Documents
constint CSIDL_COMMON_ADMINTOOLS =0x002f; // All Users\Start Menu\Programs\Administrative Tools
constint CSIDL_ADMINTOOLS =0x0030; // <user name>\Start Menu\Programs\Administrative Tools
constint CSIDL_CONNECTIONS =0x0031; // Network and Dial-up Connections
constint CSIDL_COMMON_MUSIC =0x0035; // All Users\My Music
constint CSIDL_COMMON_PICTURES =0x0036; // All Users\My Pictures
constint CSIDL_COMMON_VIDEO =0x0037; // All Users\My Video
constint CSIDL_RESOURCES =0x0038; // Resource Direcotry
constint CSIDL_RESOURCES_LOCALIZED =0x0039; // Localized Resource Direcotry
constint CSIDL_COMMON_OEM_LINKS =0x003a; // Links to All Users OEM specific apps
constint CSIDL_CDBURN_AREA =0x003b; // USERPROFILE\Local Settings\Application Data\Microsoft\CD Burning
constint CSIDL_COMPUTERSNEARME =0x003d; // Computers Near Me (computered from Workgroup membership)
constint CSIDL_FLAG_CREATE =0x8000; // combine with CSIDL_ value to force folder creation in SHGetFolderPath()
constint CSIDL_FLAG_DONT_VERIFY =0x4000; // combine with CSIDL_ value to return an unverified folder path
constint CSIDL_FLAG_DONT_UNEXPAND =0x2000; // combine with CSIDL_ value to avoid unexpanding environment variables
constint CSIDL_FLAG_NO_ALIAS =0x1000; // combine with CSIDL_ value to insure non-alias versions of the pidl
constint CSIDL_FLAG_PER_USER_INIT =0x0800; // combine with CSIDL_ value to indicate per-user init (eg. upgrade)
四、期待.net4.0
还没装.net4.0呢，好像已经扩展了SpecialFolder，比如我要获取 "C:\Documents and Settings\All Users\「开始」菜单\程序",则可以直接使用
string path = Environment.GetFolderPath(Environment.SpecialFolder.CommonPrograms);
没实际验证过，如果您验证了帮我补充一
Example:
// C:\Users\USERNAME\Documents
string path = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);