How-to-Install Oracle VirtualBox 4.3.20 on Ubuntu 14.04/14.10

Oracle VM VirtualBox is a software virtualization package for AMD64/Intel64-based and x86 computers from Oracle Corporation.

VirtualBox runs on Linux,Windows,Solaris and Macintosh hosts and supports a large number of guest operating systems including but not limited to DOS/Windows 3.x, Linux (2.4, 2.6 and 3.x),Windows (NT 4.0, 2000, XP, Server 2003, Vista, Windows 7, Windows 8),OpenSolaris and Solaris,OpenBSD and OS/2.

In this article show you how to install Oracle VirtualBox on your Ubuntu 14.04/14.10.

Add VirtualBox repository

First,edit /etc/apt/sources.list which typing The following command:
tri@linux:~$sudo nano /etc/apt/source.list

and add one of following line ccording to your distribution to your system:
For Ubuntu 14.10 ("Utopic Unicorn")
deb http://download.virtualbox.org/virtualbox/debian utopic contrib

For Ubuntu 14.04 ("Trusty Tahr")
deb http://download.virtualbox.org/virtualbox/debian trusty contrib

Add Oracle public key

After adding required apt repository in your system, download and import the Oracle public key for apt-secure using following commands.
tri@linux:~$wget http://download.virtualbox.org/virtualbox/debian/oracle_vbox.asc
tri@linux:~$sudo apt-key add oracle_vbox.asc

Install VirtualBox

Now, install VirtualBox:
tri@linux:~$sudo apt-get update
tri@linux:~$sudo apt-get install virtualbox-4.3 -y