are you SURE you cant connect? even though a firewall has been detected, you may still connect to the network as a leaf. what does the connection meter say? and what color is it? and how long do you let it connect? have you tried port forwarding your router and setting the manual port forward in advanced options? have you tried different ports to see if anything like your isp maybe filtering or throttling p2p traffic?

a vague statement like "nothing is working" doesnt give us much to work with since there is millions of other people able to use the software rather well.