|Do you mean you have a recovery DVD to restore the laptop to factory defaults?|
Normally the machine will boot from such a disk (assuming its set to boot from CD/DVD in the bios). Usually pressing F2 as machine starts booting will get you into the bios settings (may be other keys, Esc or F1 commonly - often tells you onscreen). In bios you can set first boot device to CD/DVD then it should boot from your recovery disk.
Most modern laptops also have a recovery partition you can invoke. the method of doing this varies from manufacture to manufacturer and even from model to model from same manufacturer - but if available should tell you how on manufacturer's website.