[This is preliminary documentation and subject to change]

# WWW Service Registry Entries

In addition to the parameters listed in Service-Specific Registry Entries the WWW service maintains the following parameters.

AcceptByteRanges
Registry Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W3SVC\Parameters
Data Type: REG_DWORD
Default value: 1 (enabled)
Range: 0 - 1
This value key determines whether the HTTP server will process the "Range" header for type "bytes:". If When you enabled AcceptByteRanges, the server will signals that it is accepting range requests by sending the "Accept-Range: bytes" header field, and will processes an incoming request specifying a "Range: bytes=" header field according to the Internet draft "Byte range extension to HTTP."

AllowSpecialCharsInShell
Registry Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W3SVC\Parameters
Data Type: REG_DWORD
Default value: 0 (disabled)
Range: 0 - 1
This value key controls whether the Cmd.exe special characters (which include | ( , ; % < and >) are allowed on the command line when running batch files (.bat and .cmd files). These special characters can pose a serious security risk. If the value of this entry key is set to 1, malicious users can execute commands on the server. Therefore, it is highly recommended to leave this setting as 0, the default. By default, so,these special characters cannot be passed to script-mapped CGI applets. If set to 1, these special characters can be passed to script-mapped CGI applets, with the exception of the pipe character (|) and the standard I/O redirection characters (< and >), which have a special meaning to the command processor.

DLCSupport
Registry Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W3SVC\Parameters
Data Type: REG_DWORD
Default value: 0 (disabled)
Range: 0 - 1
This value key indicate controls whether downlevel client support will be is enabled. Some older versions of browsers do not support h Host headers, which give clients the ability to access multiple Web sites that share a single IP address. If you set DLCSupport A value of to 0 means that, downlevel clients will not be supported; if you set DLCSupport to A value of 1,means that downlevel clients will be supported.

DLCCookieNameString
Registry Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W3SVC\Parameters
Data Type: REG_STRING
Default value: not applicable
This value key specifies the name of the HTTP cookie that the server sends to downlevel clients. The cookie that is sent to a downlevel client will function as a "pseudo" HOST host header so that the server can route the client's HTTP request to the appropriate Web site.

DLCHostNameString
Registry Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W3SVC\Parameters
Data Type: REG_STRING
Default value: not applicable
This value key identifies the name of the Web site which contains the downlevel host menu, which is stored in LCCookieMenuDocumentString. The downlevel host menu is a document (such as an HTML.htm file or, .asp file, and so on) which that lists all Web sites on a single IP address. The user chooses the appropriate server instance from this menu.

DLCCookieMenuDocumentString
Registry Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W3SVC\Parameters
Data Type: REG_STRING
Default value: not applicable
This value key specifies the file name of the host menu for clients that do support cookies, but do not support H host headers. The cookie acts as a "pseudo" H host header and the host menu lists all Web sites which that share a single IP address. This cookie is attached to all requests for the host until the browser session has been terminated; however, terminating the browser session does not delete the cookie.

DLCMungeMenuDocumentString
Registry Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W3SVC\Parameters
Data Type: REG_STRING
Default value: not applicable
This value key specifies the file name of the host menu for clients that do not support cookies. This file is used to resolve (or "munge") the requested URL from the downlevel client by embedding the host name in the URL.

DLCMenuString
Registry Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W3SVC\Parameters
Data Type: REG_STRING
Default value: not applicable
This value specifies the special prefix of URLs that are requested by downlevel clients. The server will check all downlevel requests against this string.

LogSuccessfulRequests
Registry Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W3SVC\Parameters
Data Type: REG_DWORD
Default value: 1 (enabled)
Range: 0 - 1
This key D determines whether or not to record successful activities in the log file. The value 1 logs successful activities, and 0 turns it off.

SSIEnableCmdDirective
Registry Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W3SVC\Parameters
Data Type: REG_DWORD
Default value: 0 (disabled)
Range: 0 - 1
To execute shell commands, the #exec cmd directive of server-side includes is used. Security-conscious sites may wish to disable the #exec cmd directive when untrusted parties are allowed to place files on the server by setting SSIEnableCmdDirective to 0 as an added security precaution, especially . SSIEnableCmdDirective does not exist in the registry by default; to allow the #exec cmd directive to execute shell commands, you must first create SSIEnableCmdDirective and set it to 1.

TryExceptDisable
Registry Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W3SVC\Parameters
Data Type: REG_DWORD
Default value: 0 (disabled)
Range: 0 - 1
This parameter key disables exception caching when calling the HttpExtensionproc() of an ISAPI application. Setting TryExceptDisable to 1 will result in any exception that is caused by a misbehaving ISAPI application to stop the server, but it allows developers to do just-in-time debugging; therefore, you should set TryExceptDisable to 1 only to debug ISAPI applications.

UploadReadAhead
Registry Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W3SVC\Parameters
Data Type: REG_DWORD
Default value: 48KB
Range: 0 - 0x80000000
When a client posts data to the server, some data is read by the server and some by the application. UploadReadAhead this is sets the default amount of data the server will read before passing control to the application. The application is then responsible for reading the rest of the data. If you increase this size, you should increase the amount of RAM on the server.

UsePoolThreadForCGI
Registry Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W3SVC\Parameters
Data Type: REG_DWORD
Default value: 1 (enabled)
Range: 0 - 1
IIS, by default, uses a server pool thread to do CGI processing. This means CGI requests that take an extended period of time can consume a server pool thread.

(The following words are used by Search; they are not intended to be displayed on the page.) W3SVC

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