This » PECL extension is not bundled with PHP. This extension is available for Win32 only. It provides functions to administrate Microsoft Internet Information Server (IIS). The extension includes function to create web sites and virtual directories as well as configuring security and script mapping. These functions have been added in PHP 4.
In order to use these functions you must enable the php_iisfunc.dll DLL inside of php.ini. A DLL for this PECL extension is currently unavailable. See also the building on Windows section.