I have five Optiplex 780 licenced for Win 7 Pro and all activated OK. Drivers and BIOS all up to date. They are 32bit and 64bit versions They all had the 'Get Windows 10' icon showing but when I try to upgrade, I get prompted for a Product Key (presumably Win 10 as the Win 7 Pro keys aren't accepted).
These are not on a domain - just separate desktops - I have used the Download tool via a USB disk except for one time I tried the lengthy process of downloading via the Microsoft site to see if it would make any difference. These were restored some time back on to larger hard disks from an Acronis image - would that be the reason ? But as I say they all show correctly as Microsoft activated.
I would appreciate any advice please.