WoW-Mania

Hi. I have two questions. First: I copied WoW from another computer in two cases (EnGB and EnUS), which I later pasted to my computer. Unfortunately you cannot change the Realmlist. I get an error: "I need to be in control of my computer and I don't have permissions." Is something wrong? What should I do? Second: What is the difference between EnGB and EnUS? thank you for any help.

It's best to download the entire game from the site and you won't have any problems.