index.php is an example of what your main page would be called.
It would be index.html unless he was intending on adding php scripting to the page.... And even there, if he ends up on a windows server the scripting needs to be done in asp.... Due to the fact that I work on a windows machine, I have a unix server installed and use than when writing php....
There are ways of using php on a windows server... I was doing a site that the guy was on a windows machine but his shopping cart was on a unix... Got real interesting....