The most sought-after ISOs are not for Spanish/French but for lesser-taught languages — Irish Gaelic, Tagalog, Swahili, Vietnamese . Those old CDs are sometimes the only decent self-study resource that existed. For these, the ISO is a preservation gem.
Newer versions of Rosetta Stone (V5 and beyond) typically do not use ISOs, as they download content directly or stream it from the cloud. How to Install Language Packs via ISO rosetta stone language pack iso
Searching for an ISO might feel like a treasure hunt, but ask yourself: Do I really need it? Legacy software has major drawbacks: The most sought-after ISOs are not for Spanish/French