Its not just that ports are open from ur own system,

By default, major ports are open if u dont have windows firewall activated. Its better U forward a port in modem rather then opening one by one.

There are 65000 ports, how many one can write one by one in firewall, So better port forward in modem.

About Still now working P2p, well ur ISP also should have allowed those ports. bcoz torent traffic will have to pass ur ISP then come to ur PC