Restoring .dat data to MSSQL

This is just a document in case I forgot to restore data files to MSSQL. I had this problem before when a colleague gave me a .dat files to be restored to SQL server. I had a 2008 version of the server and had no trouble restoring it. The problem is, I forgot how I did it when I had a new PC and I upgraded it to 2012 SQL server.

But this is a simple task (although I had a full day remembering how I did it and I had no luck finding the solution from google). First off, click restore, like so

I had trouble with the database whether or not to add a new database and restore the file to it, or not. Simple answer is no need. With the next image you can see that the configuration is very simple.

Just set it to device as the source and find the .dat file. It automatically displays a suggestion for the database name and you're done. Click OK and wait a couple of minutes for SQL server to restore the data.