Well, I ended up upgrading all my WIN 8.1 and a few WIN 7 systems to WIN 10 tonight. Glad I didn't procrastinate? :B
Fortunate to have downloaded the WIN 10 .iso file, so was able to create a couple of WIN 10 upgrade USB drives. Enough to upgrade 3 systems offline at a time.
I'm not too concerned about WIN 10 issues at this stage, as I just wanted to get these system registered for "digital entitlement" to claim the free WIN 10 upgrade. I have my own system image snapshots, so can revert these back to their former WIN 7/8.1 at any point. MS appears to indicate you can re-install WIN 10 once registered for digital entitlement.
Did disable all default enabled tracking and auto WiFi options during setup. Though wasn't expecting that WIN 10 appears to have maintained previous dual boot environment?
In this case, had upgraded WIN 8.1 to 10. Both WIN 7 and WIN 10 boot, though haven't thoroughly tested as of yet.
