The Product Key You Typed Cannot Be Used to Activate Windows
Thanks for this and other posts. With further testing and web searching I have established that, if you receive the above message, it is necessary to activate Windows 7 manually using the Microsoft automated activation phone line. This is 0800 018 8354 in the UK but if you don't get this option immediately you can:
1. Click start, and in the search box type: slui.exe 4
2. Press enter on the keyboard
3. Select your country
4. Select the phone activation option.
I got an automated service which involved typing in a lot of numbers but it worked and my Windows 7 is now activated.
Note that this was a full retail version that had been loaded once on my PC, which died, and I have successfully activated having reloaded (overwriting my hard drive) with a new motherboard.