Hi,
I did. The file PWS-php.reg comes with the bundle anyway and there I changed the path like ... ".php"="C:\Php\php4isapi.dll" and saved it in the same folder(Php) as said in the Readme file.
The other strange thing is when I tried the call a non-existing file with the extention .php(say ,my.php) on the IE ,I got the same message:
Warning: Failed opening 'C:\Inetpub\wwwroot\my.php' for inclusion (include_path='') in Unknown on line 0