A "Microsoft Registered Refurbisher" (sometimes hard to note this minor title on dealer web pages) can handle this if and only if you have the proper sticker on the laptop. Search for a "Microsoft Registered Refurbisher" in your area.
HP probably won't be able to help you out since the Hard Drive itself probably came from another manufacturer. I would trying getting a hold of the manufacturer of the hard drive ( Seagate, Samsung , etc ). Even though its an HP computer, the hard drive isn't made by HP. This is if you are trying to recover saved files or to a previous state but idk I have never needed to do this.
If you are trying to get the HDD back to the state exactly how HP shipped it out and not recover files or data then I dont know. Is there a specific reason as to why you want the Original contents on the HDD? Couldnt you just build a fresh OS on the same or new HDD?