for windows you dont need to compile it with ldap, there should be dll files packaged with the zip php came in. in your php.ini, there is a directive, extension_dir, this should point to the directory where the dll files should be placed. make sure php_ldap.dll is in the proper folder. and to finalize it, in the php.ini file, there should be a line, probably commented that says
;extension=php_ldap.dll
remove the ; from the front, restart your webserver and now ldap functions should be available.