No, you don't have to do that yet

When you deleted the preferences folder, did you make sure that LW was closed? Otherwise it won't work. And did you also look for a folder in the old and new locations? After you deleted the folder(s), did all of your settings within LW's options change back to default?

If you're sure you deleted that prefs folder properly, try changing Java versions & see if that makes any difference. Use the older version of Java, it's pretty reliable. Reboot your computer after installing the new Java.