To install Ubuntu on a computer that currently runs Windows, you need to download the installation file and burn it onto the DVD, which you can then use to install Ubuntu. Once you’ve downloaded the file, follow the instructions below to burn your DVD, depending on which version of Windows you are currently using.
Windows 7 / 8
Windows 95 / 98 / ME / 2000 / XP / Server 2003 / Vista7
Download and install Infra Recorder, a free and open-source image-burning program.
Insert a blank DVD in the drive and select ‘Do nothing’ or ‘Cancel’ if an autorun dialog box pops up.
Open Infra Recorder and click the 'Write Image' button in the main screen. Alternatively you can select the 'Actions' menu, then 'Burn image'.
Select the Ubuntu DVD image file you want to use, then click 'Open'.
In the dialog box, click 'OK'.