You can get the AdventureWorks database from codeplex site using the below link. I am going to use the 2008 version.
after successful download you need to extract it.
After successful extract you will get the data and log file.
In the next step you need to attach it with sql server using the SQL server Management studio.Login to your SQL server using the management studio .
After successful login right click on the database, this will display the context menu .
Click on the attach menu. It will display the attach database window.
Click on the add button , it will show you the locate database window.Select the database location.
After select , click on OK button, you will come back to previous window.You cab see that the selected database files are added to the window.
After this , click on the OK button and you are done 🙂 , The database will not be available to the database List.
Hope , you find this post useful . 🙂