CA TRAVELER - We just did that yesterday and put WIN8.1 back to its original state. Took over 200 MS UPDATES to get it back up with todays current UPGRADES...
It did download the FREE WIN10 ICON and we re-registered again. Now waiting for MS to send notification to continue...
I am also still waiting on the last WIN7 Laptop to get updated. We had two just alike from QVC DELL and one got upgraded a couple of days ago with no problems so this other one should go just fine. They are identical except for the case color scheme...
UPDATE: Aug 4 - Our WIN8.1 HP AMD LAPTOP got permission to continue on to the upgrade again today and all went fine after the big refresh we did to it yesterday... Guess the UPDATES needed refreshed or something... Anywho it is up and running now with WIN10.
One more to go with a WIN7 DELL INTEL LA{TOP then we done with the upgrades...
Roy Ken