Windows users will enable php_domxml.dll inside of php.ini in order to use these functions. In php 4 this DLL resides in the extensions/ directory within the php Windows binaries download. You may download this PECL extension DLL from the php Downloads page or at http://snaps.php.net/. Also, there is one additional DLL that must be made available to your system's PATH in order for this extension to work. In php 4 this is in the dlls/ directory. It's name: For php <= 4.2.0, it's libxml2.dll. For php >= 4.3.0, it's iconv.dll. And as of php 5.0.0, iconv is compiled into your Windows php binaries by default so no extra DLL is needed.