It's generally a good idea to delete your LW preferences before you upgrade to Pro. But you'll need to make a note of all your settings before you do this, b/c after you delete the prefs you'll need to reset them.
Close Limewire (LW)! Now go to your Preferences folder & view it in list mode. The LW Prefs folder will be at the top of the list & is called .limewire Now trash this folder. Drag & drop into the trash or select it & hold down both the apple & Delete keys. This will send it to the trash. Next time you open LW, you'll need to reset all your options. And LW will create a new set of Preferences.
To find which version of LW you're using, go to Help & see About... |