Computer Model, Product #, Serial #

[PavLuvDog]

Why are there 2 different sets of product and serial numbers for one machine, my new Pavilion 27?  During setup (and also by using "myHP" in the search bar I have one set of numbers, however when I registered the computer on the HP site it now gives me a different set of product and serial numbers for my new purchase.  Why is that?  Which one do I use? 

[Prométhée]

Hello
I'm not sure I understand ..
in any case, you have a product number associated with the model.
then the S / N serial number is the unique number, normally for your computer.
You should therefore have a product number, and serial number, directly on the box (in general), and in the system information of the computer.
So if you have different numbers on the site, after registration, it doesn't seem normal.
I advise you to contact HP directly

Contact HP

check this

https://register.hp.com/americas/flowPage/default/defaultExperience/en_US/faq.do#14

Q. How do I change or delete my product information from My Account?

A. Log in to My Account. View your product profile. Select "Register a product" to add more products. If an existing product is registered incorrectly, select "Remove from profile" to remove the incorrect entry. Then select "Register a product" to add it correctly.