Step By Step

  1. Eject whatever is in the CD driver (physical/virtual)
  2. Go to the command terminal and type the following:
    • $su (Then enter your password)
    • $apt-get install build-essential (Press enter and type [y] when the question prompts you and press enter)
    • $apt-get install linux-headers-$(uname-r) (Press enter and type [y] when the question prompts you and press enter)
  3. Go to devices
    • Look for: Insert Guest Addition CD image and click on it.
    • When it pops up press cancel
  4. Go to CD drive
    • Copy everything that is in the Guest Addition CD image
    • Create a new folder on your Desktop and paste it in the new folder
    • example: newfolder
  5. Go to the command terminal and type the following:
    • $cd /Desktop/newfolder
    • $Chmod +x VBoxLinuxAdditions.run
    • $sh ./VBoxLinuxAdditions.run
  6. When the VBoxLinuxAdditions finish installing
    • Type: reboot

Thats How to make Debian Fullscreen on VirtualBox. IT’S ALL DONE

Let me know how it goes.