connect to an sql server database

hello. i'm new to databases. and tryin' to learn by example. i took one of o'reilly's ado.net 3.5 samples, connectsql server, which has a connectionstring declared like this: string sqlConnectString1 = "Data Source=(local);" +
"Integrated security=SSPI;Initial Catalog=AdventureWorks;";
i put the db in the same directory as the solution's.
when i run the project, i get an unhandled SqlException:
Cannot open database "AdventureWorks" requested by the login. The login failed.
Login failed for user 'machine\adminaccount'.
i'm running vs 2008 and sql server 2005.
if there's anyone that can help me..