My English is poor, don't mind it. :)
I have 3 accounts.
Account A(paid)
Account B(free)
Account C(free, i don't use.)
Today I logged in SK with my friend's computer to showed him this game, but I logged in the wrong account.
I logged in Account C, right, the account i don't use. So I logged out account C and logged in account B.
I recommend SK to him, however something was happened.
He created a new account from official website and log in game with this new account.
"You cannot create more free account from this computer". He got the message.
Don't know why, it's really strange because he never play the game yet.
This is the FIRST TIME create a new account from his computer.
How should i do now?
This is something you and your friend should contact support referencing each other and what happened. This is an ususual situation that they will probably be able to resolve.
If your fist or better language is French, Spanish or German feel free to use that language as they have support agents capable of understanding those languages.