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.