Why though? Microsoft will stop providing security updates at some point (if they've not done so already.) I could see the advantage if you had an industrial u

Why though? Microsoft will stop providing security updates at some point (if they've not done so already.) I could see the advantage if you had an industrial use for Win 7/8, or perhaps in an air-gapped environment and for certain software. But a privacy-enhanced Firefox seems like an odd choice in such an environment.