VirtualBox Guest Additions

1. Linux

Start VirtualBox.
Start the virtual machine.
Select Devices > Insert Guest Additions CD image.

Enter the following commands at a Command Prompt with administrative privileges.

apt-get install gcc make perl
apt-get install linux-headers-$(uname -r)       # Install kernel headers.
mount /media/cdrom
cp -a /media/cdrom/VBoxLinuxAdditions.run /opt
umount /media/cdrom
/opt/VBoxLinuxAdditions.run

System is running in Secure Boot mode, however your distribution
does not provide tools for automatic generation of keys needed for
modules signing. Please consider to generate and enroll them manually:

    sudo mkdir -p /var/lib/shim-signed/mok
    sudo openssl req -nodes -new -x509 -newkey rsa:2048 -outform DER \
      -addext "extendedKeyUsage=codeSigning" \
      -keyout /var/lib/shim-signed/mok/MOK.priv \
      -out /var/lib/shim-signed/mok/MOK.der
    sudo mokutil --import /var/lib/shim-signed/mok/MOK.der
    sudo reboot

Restart "rcvboxadd setup" after system is rebooted.

The log file /var/log/vboxadd-setup.log may contain further information.

Select Devices > Optical Drives > Remove disk from virtual drive.
Click Force Unmount.
Restart the virtual machine.

To make a VirtualBox shared folder (often named sf_C_Drive or similar) available to a user in a Linux guest, you need to add your user account to the vboxsf group, which owns these shared folders.

Enter the following commands at a Command Prompt.

cat /etc/group | grep vboxsf
sudo gpasswd -a douwe vboxsf
cat /etc/group | grep vboxsf

2. macOS

3. Windows

3.1. Installation

Start VirtualBox.
Start the virtual machine.
Select Devices > Insert Guest Additions CD image.
Run the R:\VboxWindowsAdditions.exe file with administrative privileges.

Click Next.

C:\Program Files\Oracle\VirtualBox Guest Additions