Some users still possess physical installation DVDs from their original purchase. While you can technically install from these, from the PCDC. Installing from a five-year-old DVD leads to known bugs that have long been resolved.
Studio 5000 Logix Designer | FactoryTalk | US - Rockwell Automation
The Studio 5000 download ecosystem is designed around entitlement-based access, requiring a valid serial number for most full installations.