Guys as Microsoft stated before the release not all systems would have been able to update from day one...if you look at all the mess forcing update practices are doing the only clear pattern here is: don't do it and wait that Microsoft push the update for you. As far as we understand the (few) successful stories here could be simply about people trying too early to upgrade and getting Windows 10 to work by force up date just because while wasting time trying time went by..and the update arrived anyway for them as it was scheduled
Honestly..what is more frustrating messing around for hours without even understandif what you are doing, or just keep doing your stuff on Windows like before until the system upgrade arrive to everybody?
If there are some real issues in the upgrade release as soon as they become consistent Microsoft will fix them. It's a brand new OS and a brand new upgrading system...