How to install ubundu linux on virtualbox. and is it free?

subject says many _

Yes it is free.

A SINGLE.Download Ubuntu
3.Download in addition to Install Virtualbox
3 OR MORE.Create a fresh Virtual Machine
SOME.Install Ubuntu

Installing Ubuntu within Windows utilizing VirtualBox

http://www.psychocats.net/ubuntu/virtualbox

Ubuntu 12.04 Download

http://www.ubuntu.com/download/ubuntu/download

Ubuntu 12.04 (Natty Narwhal) Consumer Guide

http://ubuntuguide.org/wiki/Ubuntu:Natty

Lug.

first get a hold of it plus start set up.exe and it is ready to utilize.