I'm running OS Ticket v1.9.3 (bba9ccc) & Apache/2.4.4 (Win32) PHP/5.4.16 on Windows 2008 R2 server and want to authenticate my users against Active Directory. When I configure the settings for LDAP authentication I get the error message "LDAP extension not available".I have enabled "extension=php_ldap.dll " in php.ini file.As I understand it, this does not mean an incorrect setting, rather an incorrect configuration. How do I enable LDAP?