it don´t works fine.

Hi everyone. I´m with a big trouble using php 5 + iis 5.1 in windows xp professional. It was working fine, but suddenly stop working. under my root folder i´ve got a system folder that run php-cgi.exe fine, but files under this folder (e.g. system/function/function1.php) isn´t recognised as a php file and the browse try to open it in dreamweaver or download it. Saomeone here knows wath to do in this case? Any tip´ll be appreciated. Thanks João Cândido de Souza Neto.