Just a quick note after losing a lot of time today with this. VirtualBox (all versions) are having issues starting develop environments under Windows 10 RTM and this is affecting a lot of people who are upgrading to Windows 10.
List of relevant VirtualBox dependent projects affected: - vagrant - boot2docker - docker machine - xamarin android player - probably more...
Details: - https://www.virtualbox.org/ticket/14040#comment:25 - https://github.com/boot2docker/boot2docker/issues/1015 - https://github.com/mitchellh/vagrant/issues/6059