problems with MoP

I wanna to play frostwolf, and yesterday i download the client from this website but when i start the game in wow.exe appears
" Data/enGB/wow-update-enGB-18273.MPQ: World of Warcraft can’t make a required change to an archive file. Be sure you have write permission for the World of Warcraft folder or try running the game in administrator mode. For more information, see: https://battle.net/support/article/6910"
What i need to do ?

Stop seeding the torrent, move the downloaded client to a suitable location and remove read only mode from the entire folder (right click > properties > uncheck read only mode)