Download Ubuntu desktop os.

What is ubuntu?

Ubuntu is a community developed, Linux-based operating system that is perfect for laptops, desktops and servers. It contains all the applications you need - a web browser, presentation, document and spreadsheet software, instant messaging and much more.

Its free to use.

Types

1.Desktop Edition
2.Server edition


Download :

Desktop edition:
http://public.planetmirror.com/pub/ubuntu/releases/7.04/ubuntu-7.04-desktop-i386.iso
size:700mb
And also check this link

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