Great, that's a relief!

So is it literally the motherboard in which the Win 10 license is tied to? Would up/downgrading the BIOS affect it?

For instance, I have another license to activate on another z77 motherboard that I intend to use on a second 3570K CPU. Rather than opening the second 3570k to install onto the z77 (first 3570K was on an earlier generation MB), would I be able to take the first 3570K and place into second motherboard?

Also, regarding the MS account and linking to Win 10 license(s) (one acount for all or for each?) to prevent activation issues with hardware changes, I assume signing up to an account can be done some other time in future IF I plan to move the license to another system entirely (cross that bridge when we come to it - so to speak)?

I see that when you do sign up and link the license(s), it converts your local account to a MS account? What are the advantages / disadvantages of this? Can it be reverts back to local once you've done what you needed to do (for example to troubleshoot actiavtion etc)?

Thanks again.