With Nvidia display drivers typically consuming 400+ MB per copy (or version), keeping older drivers around is quite literally a waste of space. You can keep two versions for safety if you like, but there's no reason to have more than that in the driver store. (Before I started doing regular clean-ups myself, I might find a dozen or more Nvidia display drivers on a PC with a one-to two-year-old OS install running.)
Because you have to work at it to hurt yourself using RAPR, you needn't feel compelled to make a restore point before cleaning up your driver store. But because I'm a "belt-and-suspenders" kind of guy, I've gotten in that habit just in case I accidentally remove something it turns out I really need. You can always reload that restore point from the repair/recovery media for your OS if you wind up with a failing or unbootable machine after a too-aggressive clean-up. Who knows? It could come in handy. With a backup you can clean up whatever you want, whenever you want without fear.
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