cant log in WOW Mists of Pandaria

Hi guys,
I have a problem with logging in wow. When i enter my warmane account where it says Battle.net account name I cant log in. I receive the following message
"You must log in with a Battle.net account username and password. To create an account please [Click Here]or go to: [https://us.battle.net/account/creation/landing.xml] to begin the conversation."
I downloaded the game from this site.
What am i doing wrong and what to do to fix this problem?

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"
4) Now, log-in by using warmane account name (not email address)
5) Be sure your password has less than 15 characters