How to import a bak file into SQL Server Express

I have a .bak file, and I want to use this file to recreate the database in a fresh install of SQL Server 2008 Management Studio.

Can someone point me in the right direction on how this can be done?

I have tried:

1. right click on the Databases container within object explorer

2. from context menu select Restore database

3. Specify To Database as either a new or existing database

4. Specify Source for restore as from device

5. Select Backup media as File

6. Click the Add button and browse to the location of the BAK file

but I am getting error that

Restore failed for Server 'MyServer-PC'. (Microsoft.SqlServer.SmoExtended)

ADDITIONAL INFORMATION:

System.Data.SqlClient.SqlError: The backup set holds a backup of a database other than the existing 'invent' database. (Microsoft.SqlServer.Smo)