Using SQL Server 2005 Express and vs2008  

I am trying to add a database to the App_data folder.  When I do, I right-click, add new item, SQL Server Database, and then get the Local Database File dialog box saying Login failed for user 'MyMachine\Joe'.

However, if i go into server explorer, and add a new data connection, it works fine, and the database gets added to the instance, verified via SQL Mgmt Studio Express.

 Could anyone offer any help as to what I am doing wrong when I try and add the local file, or what settings I should look at?

Thanks in advance, Joe

 Are you trying to add a new or an existing database?

However it sounds like you have not set the permissions for the ASPNET account

Thank you for your reply.

I should have mentioned, this is on a vista-64 machine.  I have explicitly added NT AUTHORITY\IUSR and NT AUTHORITY\NETWORK SERVICE to the db logins.  In addition, I see a login for myself (MachineName\Joe),  However, I still get the error when I try and add a database to the APP_DATA folder, and the login error is for MachineName\Joe.