The database is running, that's a good thing. My guess is that the MDSHosts file is empty, if it's there at all yet. That gets generated/updated when the network nodes are changed and you're nowhere near that point yet.
You have to create a user with db restore privileges to get that backup going. This is kind of a sledgehammer approach, but what the hell, you'll be throwing out the shell db once you get the backup restored.
Try this -
[ol]
[li]Open the POS configurator and go to the Employees tab. It shouldn't promt for a password yet since there aren't any users defined.[/li]
[li]Click the Employee Classes button and add an employee class by clicking the blue plus sign. Enter a name on the new line that gets created.[/li]
[li]Go to the Privileges tab - Privilege Options tab.
Check all the options in the Database Manager section.
[/li]
[li]Close the Employee Classes form and click the Backoffice Classes button.[/li]
[li]Click Create. Enter a name, ignore the HTML stuff and assign Privilege Level 3.[/li]
[li]On the right side click the word Full, then click each of the four buttons under Compound. Go to the System Level tab and click on the word Full. Save the changes and close this screen.
(This is the sledgehammer bit. I don't know what privileges you need in here so we're just enabling everything.)[/li]
[li]Click the Configurator Access button and highlight the employee class you created.[/li]
[li]Click the blue plus sign to add a line. Select your employee class in the left column and "All Forms" on the right.[/li]
[li]Check all four boxes, save and close this form. This will give you full access to the configurator in case we have to go back in and make some changes.[/li]
[li]Click the Employees button and create a new employee by clicking the blue plus. You'll have to enter at least a first and last name.[/li]
[li]Go to the Security tab. Enter 1 in the PC Application ID box and select the classes you made in the Employee Class and Backoffice Class fields.[/li]
[li]Make sure the Change Password and Account Disabled checkboxes are blank and save.
There may be other required fields, it depends on how you loaded RES. Any other required fields will let you know about it when you try to save. Just fill them in as you're prompted. Close the Employee screen once it saves.[/li]
[li]Click the System tab on the main configurator screen and then the Restaurant button - Security tab. Make sure "Use Micros Classic Security" is checked. Make the change and save it is you have to. Close this form but leave the POS Configurator open.[/li]
[/ol]
Now try to open Database Manager. You should be prompted for a password - enter 1. That will sign you on as the new user and should enable the options in the database manager.
If you're going to be developing for RES products I'd definately recommend finding a database from version 3.2. That was the last one before all this database manager nonsense so there's nothing restricting access. Drop in a 3.2 database and log file, start up the control panel and you'll have restore access in DM.