HowTo: Install guess additions in virtualbox ubuntu guestOS

Installing guest additions

Here are a few additional packages needed for the Guest Additions.
These packages enables you to create kernel modules. For Debian and Debian based distro's like Ubuntu, you need the following packages:

dkms
build-essential
linux-headers-generic

Step1 :
sudo apt-get update
Step2 :
sudo apt-get install dkms build-essential linux-headers-generic
Step3 :
sudo apt-get install virtualbox-ose-guest-x11