Unwanted user shows up in every database

[JuanSanchez]

Every time I create a new database on of my users is auto populated into the users.
I am always there as the DBO and this other user automatically shows up.

How did this happen?
Does anyone know how to do this, I would like certain users to be auto added?
Does anyone know how to stop this once the user is no longer needed?

 

[MeanGreen]

Each time you create a database, SQL Server uses the model database to create it. Add or remove your users from that database and you should get what you want.

Good Luck.