Login server down?? Cant log in !

When i try to log in the server WOTLK from my computer i wait a while and this appears "Login server down" . When i try it from my laptop there is no problem loging in.
I first downloaded and played from my computer, after that i downloaded it on my laptop and played a couple of days, then i wanted to play from my computer again, I launch the game i type my acc and pass and a massage apears " login server down" or "redirecting me to blizz if the problem persists. "