windows 8.1 wont update to windows 10

[jncw]

My Asus transformer wont update to windows 10, I reserved it like everyone else.
It says part of the registry is missing.
I have tried to restore my transformer with the recovery key but it says it can't unlock it, input the correct key as I backed it up and printed it.
Help please

 

[popatim]

I'm confused; OEM's like Asus, store the windows 8.1key in their bios, why do you have it written down? Why isnt win8 reading the key from your bios? Is this some other kind of key?