Which web server are you using?
Make sure that the ports are correct. Put IIS on 80 and Apache on 8080.
To test the apache server, first restart the server, then in your browser:
http://localhost:8080
If the apache page appears then the server should be ok. Then configure the server you want to use with PHP.
I recommend XAMPP for someone first trying to install a php enviroment.
http://www.apachefriends.org/en/xampp.html
Otherwise search in the forum for installation instructions. There is normally an install.txt in the php directory in a win32 enviroment.