A tedious job but I make digital back ups, ISO, of all my software and then toss the disks. It's getting so DVD drives are not even included on laptops. Disk are easily scratched too.
I have a "Software" folder and in it are subfolders for the different types, like music, office apps etc.
I think that folder is 50 GB now. But everything is in it even drivers for old printers I don't own anymore.
I have Cakewalk going back to Guitar Studio6? and all are just ISO images of the original disks.
I keep a notepad document with serial numbers inside each subfolder.
This Software folder is backed up on a few hard drives some are very old now but still work. Now you could even use a thumb drive. I have it even stored off site at work.