It's not that we can't change things, is that doing so sometimes costs $10s of thousands of dollars. We often have instruments running on XP, that work completely fine, but the software will not run on 7, 8, or 10. When we contact the company to ask about an update they say "sure, but you'll need a software maintenance contract, with a re-certification fee, etc. etc, for $40k." No faculty member wants to pay $40k to move something working to a new OS when we can put it on our unrouted internal network and keep it running on XP for $0.