After installing a retail version of Windows 10 Pro 64 bit I was successful in creating a Windows 10 Pro USB System and USB Recovery. However when attempting to do a system image backup to a 2TB Hitachi external drive after about a minute received error 807800c5 error.
I noted another thread where problem was fixed by the following:

The solution is to remove the EFI partition from old hard disk.
2.diskpart disk X ( X== the number of your old HDD)
3. list partition (find what is the number of your the partition labeled as system)
4. select partition X
5. del partition override
now you can make system image back up.
you can extend one of your partitions using the newly created free spaced
go to disk management select the partition you want to extend right click on it and select extend.

I am not certain if this is specific to my problem.

Since I wish to retain the second HDD with the Windows 8.1 OEM version will this cause a problem. This disk presently has 5 partitions which are listed in order:
1. 500 MB EFI Partition
2. 40 MB OEM Partition
3. 2 GB Recovery Partition
4. 1852.10 GB OEM 8.1 Partition
5. 8.26 GB Recovery Partition

I will not be dual booting and only be using the SSD as the system boot disk.

Dell 8700 XPS
120 GB Kingston SSD with retail version of Windows 10 Pro
2 TB 7200 HDD with OEM version of Windows 8.1 Home
16 GB Memory
16 X DVD
Intel i7 4790 processor 3.60 Mhz