I'm running Debian as host and I fail to get Debian, Ubuntu, and Fedora guests to be fullscreen. Changing video memory didn't help.


  • I haven't tried any other distro
  • I didn't create WinXP guest myself

2 Answers 2


There are a few things that need to be in place. You need to have guest additions installed on the guest OS. You have to have "guest display auto-resize" feature enabled (Host+g toggles this), and then you have to actually activate full-screen mode (Host+f toggles this).

Specifically, on the Debian/Ubuntu guest, run the following (as root):

apt-get install virtualbox-ose-guest-x11
  • Guest additions not being installed is almost certainly the problem
    – Falmarri
    Nov 9, 2010 at 19:06
  • Agreed with Falmarri. Most distributions have the guest additions in the repositories, so you can look there first. Nov 9, 2010 at 19:18
  • I followed the instructions and now I got "Disable Guest Display Auto-resize" and it's not selectable. Any ideas?
    – tshepang
    Nov 9, 2010 at 21:49
  • Are you sure you installed the guest additions correctly? You compiled/installed/restarted?
    – Falmarri
    Nov 9, 2010 at 23:55
  • @Fal, must I restart the host as well?
    – tshepang
    Nov 10, 2010 at 1:04
sudo -i
sh /media/cdrom/VBoxLinuxAdditions.run uninstall


sudo -i
sh /media/cdrom/VBoxLinuxAdditions.run
  • What CD is that on? Jul 3, 2015 at 16:37
  • This question is already answered and with it's age you need to provide more detail. I'm recommending deletion 4 now.
    – eyoung100
    Jul 3, 2015 at 18:04

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