when restoring a .bak file to a SQL Server database where the .bak file was not originally backed up from, right click –> All Tasks –> Restore Database –> From device –> Select Devices –> Add your .bak file. Click OK. Click the Options tab. Now on the left side you should see the Logical file name of the database from the .bak file. On the right side under the label ‘Move to physical file name’, should be the path that the .bak file originally existed as. This field needs to be changed to the path & file name of the database you’re restoring too. After modifying those two fields, check the ‘Force restore over existing database’ and click ‘OK’.