It seems to make no difference to the problem whether that line is in or out, however I have removed it. Thanks for spotting it. The problem is as if Apache is just not functioning as a server. Yet the confirmation Apache page appears when I test it.
In I.E or Mozilla when I enter http://localhost/phpinfo.php (or any other php file taken from one of my websites) I get a '404 page not found'. If I use File, Open on either browser and navigate to C:\Apache\htdocs, I can load an html file from there but not a PHP file.
Regards
Awestruck