Virtualbox on my Windows 8.1 stopped running 64bit guests a while ago. I did not track down this problem. Now some months later i tried again and found some confusing things.
First setting:
BIOS virtualization enabled
Intel Processor Identification Utlility in 8.1: virtualization disabled
Second setting
BIOS virtualization disabledWith both settings: Virtualbox runs 32bit guests but no 64bit guests.
Intel Processor Identification Utlility in 8.1: virtualization enabled
After some searching, i realized, what was happening:
I added Microsofts Hyper-V virtualization. With that enabled Windows 8.1 is no longer a real host. It is just another guest (the most important guest) on this computer. So with Hyper-V enabled i was trying to run Virtualbox inside an already virtualized Windows 8.1.
After that it was easy: Just disable Hyper-V on Windows 8.1:
And after a restart of Windows 8.1 i was able to run 64bit guests on Virtualbox again....
Dude thanks you so much! This was breaking my mind the whole week!!!
ReplyDeleteWhat really blows my mind though is how hyper-v just turns itself on again out of the blue... All my VM's were working without fault as I explicitly had disabled hyper-v when I installed my host. It never occurred to me that it would turn on on its own.
But thanks for this post!!