If the Dell is still under warranty, it may be, as the XPS 8700 is still distributed, one can request, free of charge, a backup DVD of the original OS installed when purchased. Here's the link, and it works, because it's how I obtained mine. No phone call was made, I filled out the form & had the DVD inside of 24 hours, because I had next day business support (as a Costco member, still do, for one extra year).
I needed mine because the original recovery media set created doesn't work with HDD/SSD's smaller than what shipped with the computer. In my case, that was Windows 8, however I also installed a full retail version of Windows 7 Pro that I had & later Ultimate as a 3rd Windows option.
Many Dell owners has this benefit & doesn't realize it, have posted this numerous times to many owners, they're one of the few OEM's who'll freely give this for the asking, if under warranty. It's best to have this, even if one doesn't plan to install a SSD.