I installed VirtualBox on my host windows.
Inside I have windows 8.1. I decided to do an upgrade check. The check informed me that the following devices were incompatible: VirtualBox Graphics Adapter for Windows 8 driver.
Given that I know it should work, I decided to ignore the warning and go ahead with the upgrade. The upgrade works and I have display, but the guest addons won't recognize it properly, as I cannot use the auto-scale guest function. I installed the guest addons and updated the drivers but nothing helps.
I know its not optimal as windows feels sluggish.
Best Answer
Go to your
control panel
->system
->Device manager
and remove the display driver:Display adapters
->VirtualBox Graphics Adapter for Windows 8
:Uninstall
[v] Delete the driver software for this device
.Reboot windows and it will install
Windows basic graphics adapter
Now, install the guests addons again, and reboot the pc when it does so.
The guest addons will correctly convert the graphics adapter and after a minute or so with the new driver, the
Auto scale guest
function will scale the screen properly. In addition it will work correctly as it did in windows 8 and is not sluggish.