Problem with logging in.

Hi Warmane community!
I've just downloaded the wotlk client and I wanted to get in game, made sure the realmlist is correct and everything, and when I log in, it starts downloading some update, after which it told me to restart the game and download a patch via a blizzard application, which I didn't do. Am I doing something wrong, miss a step or something?

Make sure to execute WoW.exe and if you downloaded the client through the website, that should be enough.

I've been doing that to no result. I'll try downloading the client again.

Log in with username not email.