What product key to use-clean install downgrade to Win 10 pro from Win 11 Pro

[armyjr55]

I have a seller refurbished HP Elite Book 2570p, With Windows 11 Pro 64-bit installed by the seller, in MBR Legacy Boot mode. I've made a USB Recovery flash drive, and have product key, via a 3rd party utility that extracted that information, If I want to do a clean-install downgrade to Windows 10 Pro 64-bit, do I use that product key, or what may be in the bios from the original HP preinstalled OS (Windows 8 Pro 64-bit, or Windows 7 Pro 64-bit, through downgrade rights from Windows 8 Pro. There's an official Windows 8 Pro sticker on the bottom. Product #E78E78UT#ABA.

[Paul_Tikkanen · Accepted solution]

Hi:

You should be able to use the W8 product key that is in your notebook's BIOS to activate W10.

But before you even have to resort to that, I'm assuming the PC was upgraded at one time to W10 and then upgraded to W11.

Boot from the W10 installation media and select the version of W10 you want to install from the list (Windows 10 Pro).

Then you will be asked to enter a product key.

Select the 'I don't have a product key' option and W10 should install and automatically activate if it had been previously upgraded to W10.

If you are prompted to activate Windows, then use the W8 product key to do that.

[armyjr55]

Thank you for your prompt response to my question-I will go with your recommendations and see what happens. I don't know if the upgrade to W11 from W10 was an in-place upgrade, or a "Custom (clean install, wiping the SSD entirely) Upgrade", so I will proceed as per your recommendations and see what happens. If push comes to shove, I can use the current W11 Pro product key, as per Microsoft's recommendation. I will let you know how the process goes.

[Paul_Tikkanen]

You're very welcome.