It will depend of where the ports are blocked. So, could you tell a bit more about your connection? For example: Do you have the xDSL modem connected directly to your computer, or do you for instance have a combined router/firewall which your computer is connected to? If you have the xDSL modem connected directly into your computer, it is most likely a windows configuration issue (unless your xDSL provider blocks incoming ports on your behalf). If you have a router/modem/firewall box (as I have here) it is most likely blocked there. If so, you have to check with your provider how to unblock those ports.