I have a problem installing Guest additions in ubuntu server with kernel 3.13.0-39-generic I install whole headers for this kernel with $ sudo apt-get install build-essential linux-headers-$(uname -r) dkms
And when i do $ ./VBoxLinuxAdditions.run
Returns this error: "The headers for the current running kernel were not found. If the following module compilation fails then this could be the reason. Building the main Guest additions module ...fail! (look at /var/log/vboxadd-install.log to find out what went wrong) Warning: unknow version of the X Window System installed. Not installing X Window System drivers.
And the rest is done... i also did $ sudo apt-get install xserver-xorg xserver-xorg-core
I will gonna crazy i got 2 days looking for internet and trying everything but nothing works... It was on Ubuntu Server Thanks :)