On newer versions of Windows and Windows Server, if you've installed PHP from the Microsoft Web Platform Installer (PI) then all you have to do is add extension=php_ldap.dll to the extensions section and restart IIS.
On newer versions of Windows and Windows Server, if you've installed PHP from the Microsoft Web Platform Installer (PI) then all you have to do is add extension=php_ldap.dll to the extensions section and restart IIS.