I asked a similar question on the MS forum but got a bit confused.
When I built my last system I had a Windows 7 Retail copy and then upgraded to Windows 10 when it was free.
That PC has died and I will rebuild with the same hard drives which are still fine....
If the setup doesnt recognise Windows straight away (Plus I want to re start with a new copy as it will have the wrong drivers etc) how do I get Windows 10 back without a product key as I merely upgraded from Windows 7?
Can I use Windows 10 install media and then my Windows 7 key or do I need to call MS etc?