Thank you for contacting the Intel Communities.
I would like to recommend you to follow the instructions in here, the product key requested scenario is noted in "Troubleshooting" section in that article.
This article has all the requirements and instructions to perform the upgrade to Windows 10*.
If you require any further information or support, feel free to contact us back.
Thank you Esteban for the feedback. I have indeed followed these instructions. I have attempted to install from Windows 8.1 using the built in Windows Update feature. I even went so far as to delete all my data and applications, and ask Windows 8.1 to do a "Remove Everything and reinstall Windows". Even from this "base" install of Windows 8.1, the built in Windows Update option (Using the little Windows Logo in the system tray), results in a 'hung' install and an error in windows update.
I end up with a "C1900101-4000D" error in Windows Update.
All of the instructions (Links below) state that if you see the 8.1->10 Windows update error, revert to downloading the .ISO. But then I get stuck at the product key screen.
I have followed the instructions to download the .iSO 3 seperate times. I have attempted several online documents on how to 'reset' Windows Update after failed Windows 10 updates with no avail. Which is why I'm now at the point where I have ask Windows 8.1 to do a clean refresh, and again attempting to upgrade to Windows 10. I will use Windows Update first (again), and then try booting into Windows 8.1, double clicking the .ISO file and initiating the install from the .ISO. Which I am 99% sure will again ask me for a product key, even though my 8.1 install it is running on is Activated.
Are there any other instructions?
Thank you for your detailed explanation of this scenario.
The product key is going to be recognized by the system when using the recovery partitions of the factory-installed Windows 8.1*.
If a clean installation is done, you would loose that recovery partition as well as the key.
If you indeed followed the steps in the instructions previously provided, the next step would be RMA, here you can start this process: Contact Support
If you have any additional questions or inquiries, do not hesitate to contact the Intel Communities again.
After NUMEROUS attempts to install Windows 10 on this device, I have finally determined and able to document how to do it.
1. Reset to Factory Settings your Windows 8.1 Installation
2. Reboot apply 79+ Windows 8.1 patches (prior to Windows 10) - This can take 2-3 hours
3. Click the Windows 10 Upgrade logo in system tray.
4. Allow Windows Update to apply the Windows 10 upgrade - This can take 2-3 hours as well
You are now able to login to Windows 10 Intel Compute Stick