My practice for each new generation of device is to copy everything I am interested in to a newer technology while I still have a device that can read the old m

My practice for each new generation of device is to copy everything I am interested in to a newer technology while I still have a device that can read the old media. I have been mostly successful in capturing the files but I have a bunch that are in a format that I no longer have software to read. I lot is in folders with at least a year in their names but otherwise unprocessed. Lots of duplication. No effective way to find things I might have lost. I encrypted some stuff but lost track of the keys and the software to decrypt so that data is now lost.