I downloaded the WIN32 PHP setup and installed PHP the way it is written in the readme file ( copying the dll in winnt/system, not replacing the one already present, copying php-dist.ini to winnt\php.ini, added the key in the internet tools manager and so ... ) and PHP worked right at the first time. But ever since when I'm trying to access an old ASP script I get an HTTP 500 - Erreur interne de serveur message ..