Preparing Ubuntu Linux DVD

I. Download Ubuntu Linux
The latest LTS version of Ubuntu as of the time of writing is Ubuntu 16.04.2 LTS. It can be download from: https://www.ubuntu.com/download/desktop
The name of the ISO DVD Image file: ubuntu-16.04.2-desktop-amd64.iso

II. Create Ubuntu DVD
Burn it into a blank DVD:
My Dell Studio Desktop computer comes with Roxio DVD burner. Select "Burn Disk Image".

III. Try to boot from Ubuntu DVD
For Dell computer:

1. Insert the Ubuntu DVD
2. Restart the computer
3. In the boot menu, by either press F12 to select boot from DVD drive, OR press F2 to go to AMI BIOS setup menu. Change the first boot device to DVD drive and then save to the BIOS setup
4. Boot from the DVD drive and make sure the Ubuntu DVD is working