Windows Server 2003/2008 extra setting to Install PHP 5.2.3
Sometimes on Windows 2003 server you have followed all the steps to get PHP to run on IIS but you are still getting a strange page not found error.
It seems like it is happening for no apparent reason. You may also need to add the DLL to the web service extensions list in IIS as illulistrated below:
if you are getting a strange 404 Page Not Found Error
You click "ADD" and browse for the same "php5isapi.dll" file and click "OK"
Once completed you should see the PHP extension added on the right window pane.