You can purchase one here:http://www.bixnet.com/hpdvseindvdd.html
You can look on craigs list and e-bay. Make sure you look for the exact number that's on the dvd-rw.
Another option is to get a stand alone usb dvd burner and plug into a usb port.
(make sure you buy one with external power, as some can be powered from the newer usb2 ports)