To turn off and disable Skype usage of and listening on port 80 and port 443, open the Skype window, then click on the Tools menu and select Options. Click on the Advanced tab, and go to the Connection sub-tab. Untick or uncheck the checkbox for Use port 80 and 443 as an alternative for additional incoming connections
option. Click on the Save button and then restart Skype to make the change effective.