Working around the The server principal already exists message

While moving MSSQL users I got this message:

Server principal 'username' already exists.

The trap was that there was no such user in the list of the users of the database.

To get around it open a new query window and run:

USE master  
GO  
DROP login **username**

Go back to the tab with the query that fell off with the error and run it:

GO  
CREATE LOGIN [username] WITH PASSWORD=N'**abracadabra_with_gibberish**', DEFAULT_DATABASE=[master], DEFAULT_LANGUAGE=[us_english], CHECK_EXPIRATION=OFF, CHECK_POLICY=OFF  
GO