title: Error: "The query builder failed. Cannot open user default database. Login failed. Login failed for user <User Name>"
body: <p>I'm using Visual Basic Express 2010 and SQL Express 2008 in Windows XP. </p>
  
  <p>At first I couldn't add a datasource (the .mdf file for the database) because of a "Operating system error 32" which I seemed to have resolved by giving myself full permissions for .mdf file (by right clicking on the file and going into properties and then Security) and restarting the SQL SERVER (SQLEXPRESS) service. </p>
  
  <p>The dataset for the database is in my solution explorer but when I right click on a table adapter to add a query and attempt to open up the query builder, I get the error in the title above.</p>