Include/SkypeHTTPConflict
From wiki.visual-prolog.com
Skype (potentially) conflicts with HTTP/HTTPS servers, because Skype (by default) reserves port 80 (HTTP) and 443 (HTTPS).
As a result you cannot run an HTTP/HTTPS server when Skype runs (in default mode).
The solution is to turn off port 80/443 in Skype.
See this video: Handling port conflicts with Skype on Windows