Your backup files will not work until MS Money has been updated.
Locate the Money ‘Sample’ in the Microsoft Money 2005 folder in C:\Program Files\Microsoft Money 2005 and click on it. This will run Microsoft Money and open the 'Sample' file. Once opened Money should notify you of an update. Follow the instructions fully and once it has properly updated open up your back up file and restore it.
Hopefully the update file is still available!