You need to know what country in which it was sold  If it was sold outside of US it might not show up in Dell's US database. Try the Canadian site. Canadian seller on Ebay is not a Dell dealer. Remember Ebay is a marketplace and auction site, not Dell or an authorized reseller. It's buyer beware. The computer could be an overstock item, used, reconditioned or anything else. Here is Info about registering an Ebay item-- https://www.dell.com/support/article/us/en/19/sln143036/ownership-transfer-and-dell-product-registration-guides?lang=en