从当前进程检索所有环境变量名及其值

        IDictionary environmentVariables = Environment.GetEnvironmentVariables();
        DictionaryEntry de;
        IEnumerator enumObj = environmentVariables.GetEnumerator();
        while (enumObj.MoveNext())
        {
            de = (DictionaryEntry)enumObj.Current;
            Response.Write(de.Key);
            Response.Write(":");
            Response.Write(de.Value);
            Response.Write("<br/>");

输出信息：
Path:C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\Program Files\Microsoft SQL Server\80\Tools\Binn\;D:\Microsoft SQL Server\90\DTS\Binn\;D:\Microsoft SQL Server\90\Tools\binn\;D:\Microsoft SQL Server\90\Tools\Binn\VSShell\Common7\IDE\;C:\Program Files\Microsoft Visual Studio 8\Common7\IDE\PrivateAssemblies\
PATHEXT:.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH
PROCESSOR_ARCHITECTURE:x86
SystemDrive:C:
windir:C:\WINDOWS
TMP:C:\WINDOWS\TEMP
USERPROFILE:C:\Documents and Settings\Default User
ProgramFiles:C:\Program Files
FP_NO_HOST_CHECK:NO
COMPUTERNAME:KVCSERVER
APP_POOL_ID:DefaultAppPool
NUMBER_OF_PROCESSORS:1
PROCESSOR_IDENTIFIER:x86 Family 15 Model 4 Stepping 9, GenuineIntel
SystemRoot:C:\WINDOWS
ComSpec:C:\WINDOWS\system32\cmd.exe
CommonProgramFiles:C:\Program Files\Common Files
PROCESSOR_LEVEL:15
PROCESSOR_REVISION:0409
lib:C:\Program Files\SQLXML 4.0\bin\
ALLUSERSPROFILE:C:\Documents and Settings\All Users
VS90COMNTOOLS:D:\Microsoft Visual Studio 9.0\Common7\Tools\
TEMP:C:\WINDOWS\TEMP
OS:Windows_NT