The pop up is a little window that is titled upgrade to pro

For turbocharged downloads,get Limewire pro. We guarantee that you will love the improved performance of PRO. Thankyou for keeping the internet open by running Limewire

Upgrade to Limewire PRO.
Yes Later Why options.

This was the first install of Limewire on this system. No previous problems. The Limewire program is the 4.12.11 version. It works great. I was just wanting to get rid of the pop up.