If Office came pre-installed on a new Laptop or PC and you are looking for Microsoft office product key. Start your Office in your laptop or PC if you see options try, buy and activate, this means Laptop or PC come up with one month free trial of Office 365 Home version. Product key don’t required for a free trial office version. You can buy Office 365 subscription after One month when your trial version expire and you will get new product key with new subscription package.
When you start Office in your PC and Laptop and you are seeing only Activate options, this means you PC or laptop come up with Office 365 subscription; here you don’t need a product key to activate Office. You can use your Office product without product key.