Attaching database to the SQL server
You are connected to a SQL Server 2008 instance. The error message clearly indicates that. See How to determine the version and edition of SQL Server and its components, the section on SQL Server Database Engine version lists no less than 4 methods:


  
  Method 1: Connect to the server by using Object Explorer in SQL Server Management Studio. After Object Explorer is connected, it will
  show the version information in parentheses, together with the user
  name that is used to connect to the specific instance of SQL Server.
  Method 2: Look at the first few lines of the Errorlog file for that instance.
  Method 3: Connect to the instance of SQL Server, and then run the following query:
  
  Select @@version;
  Method 4: Connect to the instance of SQL Server, and then run the following query:
  
  SELECT SERVERPROPERTY('productversion'),
       SERVERPROPERTY ('productlevel'),
       SERVERPROPERTY ('edition');