The problem is exactly what the error is telling you... you are trying to attach the mdf file in a user instance, but at the same time you told it to not use integrated security, but SQL security... which you can't do... IF you are in fact trying to attach the database in a user instance, you MUST use integrated security.

The second error (about the db already existing) happened because quite literaly, the DB already does exist.

Sounds like you'r trying to connect to a database that already exists on the sql server ... if that's the case, then just connect to it... don't specify a user instance and don't give a path to the mdf... just use a normal connection straight up.


As a side note, where did you find that quote? I've seen that more than once now, and I don't think it's accurate information (regarding user instances being the default).

-tg