Updated: 16 April 2025
Guest additions
Select your version of VirtualBox from here https://download.virtualbox.org/virtualbox/
Download by selecting the VBoxGuestAdditions .iso file link.
Guest OS screen size
Match guest screen size to host screen size:
Probably need Guest Additions first.
Go to File > Preferences > Display.
Set ‘Maximum Guest Screen Size’ to ‘None’.
Now, view the guest OS in full-screen mode.