INSPIRON Tower WIN 10, replaced motherboard GGDJT with same, won't go beyond black screen and circling dots

For Christmas, I received a PC game that required more everything than my Dell Inspiron had to offer.

So i go by a processor upgrade to i7 from i5, additional memory (16GB), and an EVGA 2GB video card.

Running Windows 10 smoothly without any hiccups before new items were added.

After installing the video card and memory without issue, I fat fingered the processor and damaged the motherboard leads. So to correct my mistake, I replace the motherboard with a duplicate GGDJT.

Windows will start but not beyond the black screen and circling dots.

I am/ was running two hard drives. C: held the original Win 8.1 factory install and E: was where I installed the Win 10 upgrade.

Following the motherboard replacement, E: is now D: and initially wouldn't open. So now Win10 is running (albeit only in Safe Mode with Networking) on C:

All of the original Windows 10 files appear to be in Windows.old on D:

What do I need to do to get back to the original Win10 setup on D:? like it was before the hardware replacement?

Or if that isn't possible, how can I get win 10 to work beyond Safe Mode and the circling dots of doom?

Thanks in advance to anyone that can help.