
Update - have changed motherboard to one with a Win10 compatible chipset and the problem has disappeared. In summary if something in your PC/laptop is not compatible with the latest win10 update you can spend a lot of time chasing your tail until you hit a brick wall.

The PC still works well when running but I am going to change the mobo for one that supports win10.

It's not obvious until I contacted asrock who confirmed this. I don't like to be beaten and have spent a lot of time going around in circles, the PC was a high end spec when built in 2011 but the root of the problems are due to the graphics chipset on the mobo do not support win 10. Now the PC is in hibernation mode the 2nd monitor will not wake up until I restart the PC. My latest issue has been related to sleep mode start up, without going into too much detail this was overcome by changing from sleep to hibernation. I have increasingly had issues with the graphics side since upgrading to win 10, most I have lived with or overcome to a certain extent. Windows 10 allows you to customize the look of the Lock screen using the Windows Spotlight service, a single picture, or you can even showcase a collection of images from one or multiple folders. I have a PC with dual monitors and use the latest version of win10.
