win7 iis7.5 fastcgi 配置PHP问题

环境配置好了 但是$_SERVER[DOCUMEENT_ROOT]这个变量取不到 为空值
打印SERVER数组也找不到这个变量 请教下各们高手怎么处理
以下是print_r($_SERVER);输出的结果
Array
(
    [ALLUSERSPROFILE] => C:\ProgramData
    [APPDATA] => C:\Windows\system32\config\systemprofile\AppData\Roaming
    [CommonProgramFiles] => C:\Program Files\Common Files
    [COMPUTERNAME] => CHX-PC
    [ComSpec] => C:\Windows\system32\cmd.exe
    [FP_NO_HOST_CHECK] => NO
    [LOCALAPPDATA] => C:\Windows\system32\config\systemprofile\AppData\Local
    [NUMBER_OF_PROCESSORS] => 2
    [OS] => Windows_NT
    [Path] => C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files\Common Files\Adobe\AGL;C:\Program Files\Microsoft SQL Server\90\Tools\binn\;d:\Program Files\Windows7Master;D:\Program Files\Windows7Master;
    [PATHEXT] => .COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC
    [PROCESSOR_ARCHITECTURE] => x86
    [PROCESSOR_IDENTIFIER] => x86 Family 6 Model 23 Stepping 10, GenuineIntel
    [PROCESSOR_LEVEL] => 6
    [PROCESSOR_REVISION] => 170a
    [ProgramData] => C:\ProgramData
    [ProgramFiles] => C:\Program Files
    [PSModulePath] => C:\Windows\system32\WindowsPowerShell\v1.0\Modules\
    [PUBLIC] => C:\Users\Public
    [SystemDrive] => C:
    [SystemRoot] => C:\Windows
    [TEMP] => C:\Windows\TEMP
    [TMP] => C:\Windows\TEMP
    [USERDOMAIN] => WORKGROUP
    [USERNAME] => CHX-PC$
    [USERPROFILE] => C:\Windows\system32\config\systemprofile
    [VS90COMNTOOLS] => D:\Program Files\Microsoft Visual Studio 9.0\Common7\Tools\
    [windir] => C:\Windows
    [HTTP_CONNECTION] => Keep-Alive
    [HTTP_ACCEPT] => */*
    [HTTP_ACCEPT_ENCODING] => gzip, deflate
    [HTTP_ACCEPT_LANGUAGE] => zh-CN
    [HTTP_COOKIE] => cnzz_a1301743=15; sin1301743=; rtime=1; ltime=1268096828729; cnzz_eid=41766987-1268034467-
    [HTTP_HOST] => localhost
    [HTTP_USER_AGENT] => Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; Trident/4.0; QQWubi 133; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; WWTClient2; TheWorld)
    [HTTP_X_REWRITE_URL] => /indexxx.php
    [APP_POOL_ID] => 525rcw
    [AUTH_TYPE] => 
    [AUTH_PASSWORD] => 
    [AUTH_USER] => 
    [CERT_COOKIE] => 
    [CERT_FLAGS] => 
    [CERT_ISSUER] => 
    [CERT_SERIALNUMBER] => 
    [CERT_SUBJECT] => 
    [CONTENT_LENGTH] => 0
    [CONTENT_TYPE] => 
    [GATEWAY_INTERFACE] => CGI/1.1
    [HTTPS] => off
    [HTTPS_KEYSIZE] => 
    [HTTPS_SECRETKEYSIZE] => 
    [HTTPS_SERVER_ISSUER] => 
    [HTTPS_SERVER_SUBJECT] => 
    [INSTANCE_ID] => 1
    [LOCAL_ADDR] => ::1
    [LOGON_USER] => 
    [PATH_TRANSLATED] => E:\525rcw\indexxx.php
    [QUERY_STRING] => 
    [REMOTE_ADDR] => ::1
    [REMOTE_HOST] => ::1
    [REMOTE_USER] => 
    [REQUEST_METHOD] => GET
    [SCRIPT_NAME] => /indexxx.php
    [SERVER_NAME] => localhost
    [SERVER_PORT] => 80
    [SERVER_PORT_SECURE] => 0
    [SERVER_PROTOCOL] => HTTP/1.1
    [SERVER_SOFTWARE] => Microsoft-IIS/7.5
    [UNMAPPED_REMOTE_USER] => 
    [ORIG_PATH_INFO] => /indexxx.php
    [SCRIPT_FILENAME] => E:\525rcw\indexxx.php
    [PHP_SELF] => /indexxx.php
    [REQUEST_TIME] => 1268096829
    [argv] => Array
        (
        )    [argc] => 0
)