Download a copy of linux, Mint will work most like what you are used to, and burn, not copy, it to a dvd.
http://www.linuxmint.com/download.php When you start from the DVD you will see your hard drive listed in the files folder in the bottom left toolbar area.
Not only can you now transfer all your files elsewhere, usb flash or external drive, you also can look at a free alternative to the soon to be unsupported XP.
Mint is most like the XP desktop but Ubuntu is probably easier to learn and uses more ram, both would do the job and are very, very user friendly.