Ok let try this way.On you UI at
C:\Documents and Settings\Your name\My Documents\The Lord of the Rings Online\Ui\Skins
folder remove all the themes that you extracted here on the folder skins.
After it is empty,extract the folder jappme ivy only and is should look like the pic below.Also are you using Win Xp or vista?Think vista is a different location then above.
also to enable UI is at options in lotro ingame under Ui setting like in the walk through F.A.Q
Also are you using winzip or winrar or 7-zip to extract?
If you dont have any those programs,here a link to get the 7-zip.Its open source free to use.