Well just to make things legal here, if you do own the original copy and you want to boot up with the backup you should had copy it as an image and burned it, this wouldn't be a problem, it should be able to boot. There are ways to make it bootable using Nero, but I won't discussed it, but I won't stop you and remember Google.com is your best bet.
On another note, make sure your BIOS is set to boot from CD before Harddrive.