This is a Q&A post after sharing Guide for installing Ubuntu in VirtualBox on Windows1. If the resolution of the installed guest OS on the VirtualBox is too small(For example 640x480) and you cannot adjust it through System Settings -> Display, what should you do?A: In this case, it is mostly probably you don't have the VirtualBox Guest Additions installed. You can install the Guest Additions on your guest OS by:sudo apt-get install virtualbox-guest-dkmsThen restart the VM and you will see the resolution you want.2. How to share a folder from guest OS to host OS. The guest OS is Ubuntu ...