Can't open the client.

So I just downloaded this client, and whenever I try to open it, I get an error popping up (I'll put a link to the screenshot containing this error). Anyone know what I can do to change this so I can play?

https://puu.sh/wkgb3/9a1e0a84bf.png (screenshot to the problem that occurs)

Follow these steps:
1) Restart your PC ( this is important)
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".