Virtualbox 6 doesn't let me resize the virtual screen. What could explain this issue?
The "scale to 100%" stay selected even though I tried to manually select other resolutions.
Using Microsoft Windows 10 as host in Microsoft Windows 7 as guest.
The guest additions are installed:
Do you have the guest additions installed? They are required for this to work. Resizing without the guest additions does not affect the guest resolution, since the OS itself must know about the resolution change and there is no mechanism other than guest additions that can deliver this information to the guest OS.
The easiest way to resize is to use the Virtualbox menu View > Auto-resize guest display.
You may then resize the VM to any desired size.
If this doesn't help, try to select for the VM some other Graphics Controller for its emulated hardware.
