Apple products do not work with HP Windows systems.
I was sent a verification code to redeem my gift card. But, because it was an Apple gift card, was required to go through Apple's accounting system, iTunes and Apple Account, both of which I had to create. But, my card never actually showed up. It disappeared into the internet ether, because Apple products to no recognize and acknowledge the existence of HP Windows systems. So, electronically, the system is broken and does not work.