The Steam Account has been used to login into another computer...

I just recently installed my garrysmod onto my brothers desktop in order to get more frame rate. Well shortly after I went to my friends house. My brother completely shut his computer before I got there. Now I’m at my friends house and it just keeps giving me this when I try to play a Multiplayer game:
The Steam Account has been used to login into another computer.To Continue using steam you need to log in again.

I press login and it takes does absolutely nothing. It stops on parsing game info. My brother even uninstalled steam. I dont know what else to do. PLEASE HELP

Forgot to say, that Im using a laptop which is what I originally had before I downloaded it on my brothers computer

Remove clientregistry.blob, found in the main steam directory and restart steam.

Thanks you so much :slight_smile: