I have one question . I started on blizzard , realm Uldaman and now I need some interface to install .
Where do I have to put the files .
I put them in wow dir /interface/addons but it's not working . I checked extension of file ( addons that come with wow and one that I installed there ) and they are not the same .

There are PUB extension and BLP . Tell me if I'm wrong but I think that these extensions are not correct or something .
Please help I really need this addons .

Chances are you had the "Use folder names" option checked when you unzipped. So the add on your trying to use is possibly in addons/interface/addons/****

And in your character screen, click on the AddOns Button in the bottom left-hand corner and check the 'Load Out of Date Addons' as well because some addons that are still great but are not updated anymore may not load because of this.

Yeah I did it , thanks guys