download the latest version on a different PC and use Microsoft’s Media Creation Tool to create installation media on a 4GB or larger USB thumb drive.
You must select the option to “Create installation media for another PC” and choose the correct version for your laptop (64-bit Windows 10 Home, or S as these small machines often come with this cutdown version of windows 10).
You may also need to set your laptop to boot from USB.
You don’t need a product key as your Windows 10 activation is stored online against the Microsoft Account you use to log on.
You can use this approach to “Start fresh with a clean installation of Windows 10” as per Microsoft’s instructions.
However, it removes all the programs that are not part of Windows 10, including your manufacturer’s apps, support apps, drivers, customised power and sleep settings, etc. While you can opt to keep personal files, you may lose digital licenses and related content you have paid for. You must back them up.
It’s not as simple as letting Windows 10 auto-update, but at least you’ll end up with the latest version of Windows 10 and the maximum amount of free storage space.