Mine finally works!

I disabled the new Windows firewall and when I looked in my McAfee file, found that for some reason, my LimeWire connection had been disabled (I didn't do it). I allowed access, deleted the .limewire preference files, made triple sure that Limewire wasn't running, downloaded the jar files into the Limewire program file and restarted.

I've been trying to fix this for a few days, so I guess my only suggestion is patience and try everything. I had no reason to think McAfee would suddenly drop LimeWire from my allowed programs, but it did (and it was the only thing changed). I also made sure the Windows firewall was absolutely disabled (there are two or three areas where you have to tick a box off to disable).