When does HP Care Pack begin to calculate 3 years?

Three-year free door-to-door service starts from the purchase invoice, and starts from the chassis factory date if there is no purchase invoice. This service contract shall be signed at the time of purchase. This is the first time I've heard that you follow up the warranty when there is a problem, but his three-year warranty includes a one-year warranty at the time of sale, which means that you spent 199 yuan to buy two more years of service.

It is unlikely to be tricky, because HP's terms of service should be written in detail.