Suddenly I have a firewall?
 

I've been using Limewire for ages. Two days ago I tried to connect and suddenly I am behind a firewall.

There have been NO changes to my computer, my Windows, my modem, nor my router in ages.

I have NO firewalls in place on any of the above applications or hardware. I had none, and I have none. What is my Limewire suddenly detecting?

Thanks in advance.