Hi ImmyDoyle,
Welcome to the Microsoft Community! We appreciate you taking the time to reach out and consult this doubt with us. I can certainly see why this is important and concerning to you, so please know we will try our best to guide you in the right direction!
As shown in the following support article: **Surface standard warranty and Microsoft Complete for Surface**, your new Surface comes with a one-year limited hardware warranty and 90 days of technical support, but in addition to the standard limited warranty, you may also have the option to purchase additional protection for your Surface, which is called Microsoft Complete.
If this is the case, and you acquired such additional protection, yet, when you try to register your device, it shows your warranty expired, we suggest you contact the Store where the Surface was purchased as well as Technical Support here.
Furthermore, please read the following support FAQ regarding the Surface warranty:
We hope this information is useful. If you have any more questions or concerns, please don’t hesitate asking.
Cheers,