This short tutorial will shows you how to install VirtualBox guest additions on Windows. Guest additions consist of device drivers and system applications that optimize the guest operating system for better performance and usability.
In this tutorial we are using windows server 2016, however this guide should work on most versions of Windows.
First click on Devices and then click insert Guest Additions CD Image
Next navigate to Computer / this PC
Now double click on VirtualBox Guest Additions
We then clicked on the VBoxWindowsAdditions-amd64 (if you are running a 32bit system you can select the 32 bit version)
Then simply step through the wizard to complete the installation.
When prompted reboot the system when it is fully rebooted you will have guest additions installed.
A full video tutorial can be found here: