If this is/was a backup of a whole computer installation, then you are talking thousands, if not hundreds of thousands, of files. That is not going to be easy.
You don't say in what format these recovered files are listed. Do they have both a file name and file extension, of only one of those, or has the recovery software given these files it's own file name?
If the recovery software has managed to provide original names and file extensions, eg "MyPersonalDetails.doc", then that should be available to be opened. If it gives no extension, but just the original file name, eg "MyPersonalDetails", then you could take a punt and assume it is a .doc file, and rename the file to add the .doc file extension. or if you use some other word processor, whatever file extension that software saves files as.
The same for images, .jeg, .bmp, etc.
If these files list in a file manager like Windows own "Windows Explorer", then you can change the list order into 'file type' by clicking the File Type column header. That might make searching for your own known file types easier. But it is still going to be a long and arduous task.
You don't say what you want to achieve with all of these files. A reinstall of the OS looks out of the question.
Mark