-> Check " Use ports 80 and 443 as alternatives for incoming connections. "
(It helps to have a little more flexibility in terms of bandwidth)
-> In the properties of your Internet connection :
-> In Properties of " My Network Places "-> Properties [" Internet Connection "]
-> Tab " General " or " Network Management ":
-> Uncheck the option " QoS Packet Scheduler . "
-> IMPORTANT: Disable the "Server" service.
-> Go to " Start Menu "->" run "->" services.msc "
-> Stop and disable the " Server " .
(If this is activated, it allows anyone on the Internet to access anything that is shared on your computer. It is therefore strongly advised to disable it unless your machine is really a server)
Incidentally, if your connection is clamped on ports greater than 1024 (anti-P2P clamping, strapping on professional network ...) . So it is advisable to change the port specified by Skype and to choose a new one that will lower it to 1024 .