Admins, Surface Area Configuration

Up til now i've been working with Access, i have only got a few weeks experience with SQL, so dont eat me.

I set up a SQL Database, and placed it into my site, etc, set up all the connection strings. It connects fine, but cannot log in.  It tells me;

Cannot open database "C:USERSJAREDDESKTOPSTYXSTYX - BUILD 2APP_DATASTYXDB.MDF" requested by the login. The login failed.
Login failed for user 'Webdev01Jared'.

I'm running Vista (x86), and SQL Server 2005 Express SP2, and i'm aware that Vista by default does not automatically enable remote access in SQLExpress for local admins.

 So i go into Surface Area Configuration. I've read about it, and it's two steps, Click "Add New Administrator", then select the priveleges in the left box and click the button to put them in the right box. Simple enough, and it works, sure, click the button, it moves across, done.

But. Hit OK. It's done nothing, i still cant connect, and the cherry on top; open up the SAC again to check and there is nothing in the right box. It's exactly how it was before i changed it. The problem is definitely this, and not the account, as i can log in for SQL Management Studio just fine, with the same windows authentication credentials.

 Thanks in advance.