I have an HP Stream 14 currently running Windows version 1607. It kindly keeps telling me Windows isn't supporting this version anymore and I need to update to the latest version. This is proving a little difficult as I have, for some reason, zero space available on the drive.
I found some info saying to run some Windows tool (doesn't seem to be the Media Creation tool or, at least, it isn't called that on this page) to install a fresh copy of Windows but that the space needed is 3GB. A little difficult as I don't have that space available which is why I'm having this trouble in the first place.
Windows 10 activation licence key is embedded in the BIOS chip on motherboard. The key automatically activates Windows 10 upon installation while connected to internet, provided you're installing same edition i.e., Windows 10 Home.
You can try the below suggestion to clean install Windows 10 latest build,