So. What steps do I take now that I'm totally replacing my hardware? As in, Motherboard, CPU, RAM, HDD's/SSD's, the lot. Only things that will be original, are PSU and case, and I can't see Windows 10 remembering them? Phone call to MS I guess?, or is there something easier? I could use another Technet key, but I'd rather not.
Microsoft defines that as a new computer and you're correct, Microsoft can't "remember" what's it has never seen before; hb860 is correct.
I did replace my mother board and CPU an half year ago started up and not activated anymore ! So I called MS they simply tould me to buy an key in the store I said no way is there an other way to activate then ? Then they told me to go back to an earlier winddows activate and upgrade ! So figure it out maybe I had the wrong person on the phone that day or is that the policy they use for every body
Been there; done that. I had one problematic computer that should have easily upgraded to Windows 10 ... but it didn't. So, I bit the bullet and started over by doing exactly what Microsoft told you to do. I had plenty of time so why not. The process worked perfectly and Windows 10 on that machine is running extremely well. The first time I tried to install 10 I did so via the suggested upgrade route by starting the installation from within Internet Explorer. The second time I used the downloaded Media Creation Tool. For all I know they may be the same. But I now use the tool exclusively and so far it's worked every time.