XP
You can still claim your free windows 10 upgrade if you use accessibility features
Given that you're contemplating changing OSes, have you factory reset it? that might help, but you'll likely need to renuke the bloatware and obviously reinstall whatever else you need.I'm fine with 10 on our laptop that came with 8. But it has a lot more grunt than your current setup. There do seem to be some specific tablet features that worked better in 8 that are a bit of a PITA on 10 now. Keep that in mind with your hybrid thing.