I hope you already know the answer to this question, but if you don’t know the answer, here it is:
1- Open SQL Server Management Studio.
2- Connect to the SQL server.
3- Right click on the database.
4- Select properties.
5- Select options.
6- On “Auto Shrink” set the value to “false”.
7- Click on “OK”.
I hope it helps. There are many other options you can change, I advise you to check SQL Server Books Online before you change anything.