What do you see if you type localhost or 127.0.0.1? Do you see that standard apache page that your install was succesful? If you do open up the httpd.conf file of apache.
Search for Documentroot.
Then change the sentence in:
DocumentRoot "C:/MyWebsite"
Or just the pad to where your php file are.
Scroll down a bit and you'll see
<Directory "something something">
Change taht one in to
<Directory "C:/MyWebsite">
That should do the trick.