no wifi signal on 12.04

Hello again,

When I was online last night, my wifi signal was lost and I couldn't get it back. It doesn't even show on the desktop. I called the service provider and everything is ok on their part. The lights on the modem are all green. so I suppose there isn't any problems there. Now I'm on ethernet. I have Ubuntu 12.04 LTS, I keep on updating it, and maybe something isn't compatible. The wifi radar can't locate the signal...even though the modem is in the same room. I am patiently waiting for the new LTS, and am hoping these bugs will be solved. But in the meantime, is there something that I can do? Again, thanks in advance for any help.

Or maybe I can install 14.04 now, is it stable?