Problem with launching wow

Hello,

My friend just downloaded wow - Mists of Pandaria from Warmane website and he cannot launch wow clicking on wow.exe. It says "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.

I didn't have this problem. Any ideas what can be wrong?

Thanks.

follow these steps:
1) Restart your PC
2) close your Torrent client and move your WoW folder away from your Torrent's download destination
3) now right click on WoW folder> Properties> remove "read-only".

Thank you! It works now