Restored files have are unreadable with .nba extention. How can I open them all so I can read them?

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I have Nero 2018. I backed up my computer a few days before it crashed. I have a new computer and I tried to restore to a folder which seemed to work but now I have hundreds of files that have .nba extensions and are numbered in a strange list of numbers. I have no idea what is what so how can I convert them into something readable? Thanks.