Windows 10 Guest freezes on initial boot under virtualbox in Ubuntu 16.04
Solution 1:
You may have an old version of VirtualBox.
I had this problem with a Windows 10 guest on a Ubuntu 16.04 host and solved it by removing VirtualBox 5.0.40 (sudo apt-get autoremove 'virtualbox*') and then installing VirtualBox 5.1.24. https://www.virtualbox.org/wiki/Linux_Downloads
Use VirtualBox --help to see your version of VirtualBox.
Solution 2:
on that version 5.0.40 you can try to unset paravirtualization. on your VM configuration Under System – Acceleration you must set Paravirtualization to None.