You will need to call Dell Canada -- there will be a charge for the media if you're out of warranty. 
Hi, I recently tried to restore my laptop but one of the dvds containing the recovery image was damaged, causing the restoration to fail.  I browsed through the support site but I haven't found a way to download the images for the recovery media.Is there any way to get the dvd's/iso's? By the way, I live in Canada and the laptop is an Inspiron 17R 7720 SE  Thanks in advance for your help Martin.
Factory reset media? 