issue logging in wow client

[Ktulu1720]

trying to get a friend to play and everytime he tries to log in it wont work keeps telling him to create a battlenet account and he is logging in with the same username and password he uses here on the website is there a fix for this ?

[Walabala]

Check your realmlist in the Config.wtf file and clear Cache folder.
If everything is ok but the problem is still exist then delete everything in the WTF folder(make sure you have a copy from it). Run Wow, if you're lucky it will run perfectly, if not copy eveything back to the WTF folder and run Wow, it should works if I'm right.