My new computer has been supplied with Vista installed. I would like to add windows XP pro and run two OS independently. Can this be done? How?
Thanks

You would have to wipe the drive, install XP first, and reinstall Vista on a separate partition. It will then install a bootloader so you can choose which version you want to use every time you boot the computer.

Here is also a useful guide:

http://apcmag.com/5485/dualbooting_vista_and_xp