For anyone curious, upgrading from 9431 DOES WORK. There was a user earlier who had problems, so unless I'm extremely lucky, he probably had something else incompatible - probably a third-party antivirus or firewall. for anyone interested, I simply extracted the installation iso to a directory on a non-system drive and changed the cversions.ini file to require a build of no less than 9430. Windows Defender, built into Windows 8+, includes the antivirus capabilities of MSE. Personally, I've been happy with MSE since it was in beta, but it's up to you. Windows Defender is *automatically disabled* in this build, but easily able to be activated through action center.
Odd my was running from the first boot maybe key has something to do with it Also used free mce key it work to
Skype is already available in this build, but it's not placed on the Start screen. Just go to the Start screen, search for Skype and you'll see that it's pre-installed and you can launch it right away.
It doesn't matter at all. There's no need to work on cause very very soon nobody will even talk about it anymore. RTM is around the corner! No need to bother or fight about. ;]