Manually Installing VirtualBox Guest Additions: Trying to install guest additions from the menu and it does not work?
Normally, you can install guest additions from Devices->Install Guest Additions from the VirtualBox Menu. But this can be a pain to get to install from the menu, so I just run the installer manually from inside the ISO.
1. You will need to Download 7zip
Note: To enable 3D hardware acceleration, check the box labelled Direct 3D Support
Note: Choose to install 32-bit VBoxGuestAdditionsx86.exe or 64-bit VBoxGuestAdditions-and64.exe depending on when operating system you installed
Just follow this guide and your be up and running in full screen in no time. (Remember to select 32-bit or 64-bit and if you want to install 3d hardware acceleration)
For full screen click full screen button ————>