apache error log stampa il seguente messaggio all'avvio del servizio

codice:
PHP Warning:  PHP Startup: Unable to load dynamic library 'c:/wamp/bin/php/php5.3.0/ext/php_mssql.dll' - Impossibile trovare il modulo specificato.\r\n
 in Unknown on line 0 
[Sun Nov 21 16:43:21 2010] [notice] Apache/2.2.11 (Win32) PHP/5.3.0 configured -- resuming normal operations 
[Sun Nov 21 16:43:21 2010] [notice] Server built: Dec 10 2008 00:10:06 
[Sun Nov 21 16:43:21 2010] [notice] Parent: Created child process 3844 PHP Warning:  PHP Startup: Unable to load dynamic library 'c:/wamp/bin/php/php5.3.0/ext/php_mssql.dll' - Impossibile trovare il modulo specificato.\r\n 
in Unknown on line 0 
 
Warning:  PHP Startup: Unable to load dynamic library 'c:/wamp/bin/php/php5.3.0/ext/php_mssql.dll' - Impossibile trovare il modulo specificato.  in Unknown on line 0
 
[Sun Nov 21 16:43:21 2010] [notice] Child 3844: Child process is running 
[Sun Nov 21 16:43:21 2010] [notice] Child 3844: Acquired the start mutex. 
[Sun Nov 21 16:43:21 2010] [notice] Child 3844: Starting 64 worker threads. 
[Sun Nov 21 16:43:21 2010] [notice] Child 3844: Starting thread to listen on port 80.
è possibile che php_mssql.dll che ho scaricato sia incompatibile con win 7 64bit??