I did not lose anything. All my libraries were still in tact. The key is to check your Control Panel for Add or Remove Programs (whether you've got XP or Vista makes no difference). If you see more than one Java 6, then you need to uninstall all of them from the Control Panel prior to installing the off-line download of Java 6. BTW I did the full install of the Development plus Runtime.
Then uninstall LW using the Uninstall script in the LimeWire Program Folder.
The next step would be to reboot before installing anything.
Then install the off-line download version of Java 6. Then you might need to reboot again (I'd probably do it anyway just because you're using a Microsoft Operating System).
Then install LW, but uncheck the box to launch LimeWire. Then you can find the gnutella.net file under your username folder Application Data (or AppData if you've got Vista) and check its size. It will most likely be 1kb. If so, it's bad - bad - bad. Delete it, and copy a new one in its place. A good version of the gnutella.net file will be over 21kb in size.
Then you should be able to start LW with no problems at all (hopefully).