Try this...

Obtain a firewall. This is a MUST. Sygate is more than adequate and I thoroughly recommend it. Install, reboot yadayada.

Make sure Windows own firewall is disabled.

Log into your router and enable DMZ (it's in the settings, look for it). DMZ is de-militarized zone and it stops the routers protection... but seeing as you installed a firewall you should be fine.

Done? Reboot. Go back in and make sure settings are still ok.

Try loading up your p2p client again.

If it still doesn't work, change the ports to something else as your ISP may be blocking the ones you're using.