If it's Linux, you'll have to mount and open the cdrom (which will now contain the Guest Additions ISO file), then launch the appropriate executable program from those displayed. If it's Windows, the Guest Additions wizard will open automagically and you then follow its instructions. What you do next depends on the guest system. Finally, run the VM and after the guest system boots, pull down the 'Devices' item from the VBox menu bar and select 'Install Guest Additions' which should be the bottom entry of the drop-down submenu. Once you have done that, create one or more new VMs and install their guest systems. After installing vbox 5.0, use its internal menu's 'Extensions' choice to locate and install the extensions package (which you might need to download separately). I am trying to install guest-additions in VB 5.0. Accept that and after the update you will have to re-run the new n file. That should be done until you next upgrade the VBox version, at which point you will get an error about guest additions being out of date and offering to update it. iso of the distro of your choice you will need to boot to it, then insert the guest additions from the devices menu, and finally as root run the /media/user/VBOXADDITIONS_5.0.4_102546/n. When you now make a new virtual machine from an. Now get hold of the guest additions if you don't already have the package from Oracle VBox website, but if it is already on your disk somewhere just double click on it and it will be installed in VBox. Do not try to install the guest additions from the repos as they are not available that way for the 5.0.4 version.

If you have currently removed VBox from your machine, install it again from the repos, assuming, of course, that you have the VBox repos enabled as I have. OK, here's what I think you must do to get VBox 5.0.4 working properly.

Virtualbox extension pack 5.0