Follow these steps to create a proper backup file that can be restored over your Alentus SQL Server 2005 Database as required:

1. Using SQL Management Studio, right click on database, choose "tasks" > "backup" and on the "General" page, ensure that the following settings are made:

- Backup type: Full
- Backup component: Database
- In the Destination window, the nightly backup location will probably be selected, to avoid overwriting them, click "Remove" > "Add" > then choose a foldername that SQL Server has permissions to write to, then an appropriate filename with the ".bak" extension.

2. Click on the "Options" page and ensure that ONLY the following items are selected:

- Backup to an existing media set
- Overwrite all existing backup sets
- Verify backup upon completion

3. Click "Okay" to create backup file. You should receive the message "Backup of database <yourdbname> completed successfully".