If you a webmaster, or someone that must use Skype and webserver (IIS or Apache), you may find that you can not active both of them together. I have experience with that. When I activate my Skype, my webserver/localhost can not work.
Finally I found the problem when I try to Edit some Options or Setting on the Skype. In default condition, Skype use port 80 as alternatives incoming connections. So, to avoid the conflict between skype and webserver, you just disable (see image) the option.
You can do this by access Skype, then click Tools > Connection Options. You will see that that “Use port 80 and 443 as alternative for incoming connection” option is check. You just uncheck this option and problem solved, you can use Skype and your webserver together.