I recently installed Skype on my Windows 7 system. I also periodically run WAMP Server.
Started WAMP over the weekend, but nothing would show up in //localhost or any sub folder. When I ran WAMP / Apache / Service / Test Port 80 I got a message "Server: May be Skype"
I shut down Skype and restarted all services and then Test Port 80 reported "Server: Apache/2.2.22 (Win64) PHP/5.3.13" and everything worked fine again.
I then restarted Skype and everything still works.
So just a heads up, if you use Skype and WAMP Server, you need to start the server before running Skype.
Normally I only run WAMP when I am testing some new php code. So this was a surprise when it all stopped working.