Ubuntu – Unable to turn on seamless mode in VirtualBox

You will need to install the kernel modules (headers) package that match the kernel version you are running the Ubuntu virtual machine with.

Type the following command in the terminal:

uname -a

This will give you line like this:

Linux dirk-Studio-1558 2.6.38-9-generic #43-Ubuntu SMP Thu Apr 28 15:23:06 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux

The first word is the type of system, the second is the name of your machine and the third one is the one you are looking for. It gives the kernel version.

So you need to install the linux-headers-{my kernel version here} package from Synaptic org using apt-get. In my case it would be

sudo apt-get install linux-headers-2.6.38-9-generic

or directly in one generic command:

sudo apt-cache search linux-headers-`uname -r`

Hope that helps!

edit:

Ok, if that is setup correctly you can try to install the packages listed here Check post #12

This works for me - with reservations! I obeyed all the standard instructions from the documentation (update, upgrade, install dkms, reboot, then install Guest Additions and reboot again).

The problems start in Full Screen or Seamless mode where it appears the the screen refresh is broken - for example you get up a Terminal and start typing - nothing happens. Click OUTSIDE the terminal and all your typing magically appears. Reverting to windowed mode fixes this and the system works including cut and paste between Windows and Ubuntu.