Well, MS isn't on my Christmas card list...
The Windows 10 upgrade could be initiated from a USB drive. It didn't seem to care about the graphics card driver. The upgrade went okay at first. I was able to load the Windows 8.1 x64 driver for the graphics "card" without issue. I got drivers loaded for everything except my Mellanox 10GbE Ethernet card. I downloaded the latest driver package from Mellanox and was greeted with the Windows 10 BSOD equivalent screen during the driver install process. It would BSOD during every boot on one of the driver files. I finally got that stopped, but nothing I did I was able to get the card working. I ended up deciding to clean install the system with the 10GbE card removed.
Unfortunately, during the clean install for some inexplicable reason the installer decided to write the 500MB system reserved partition to one of my empty HW RAID arrays hanging off the hardware RAID card in the system despite my telling it to install Windows 10 to the SSD RAID-1 array. As soon as I saw that I pulled the arrays and clean installed Windows 10 again with only the RAID-1 array of the SSDs in the system because I knew that wasn't going to be fixable faster than reinstalling. I was able to get all the drivers installed for the HW in the system. Then I added the 10GbE network card got a BSOD equivalent during boot, but it was fine after the reboot. Windows found some drivers for the Mellanox card and installed them. I then installed the driver & tool pack from Mellanox. No BSOD this time and everything was happy.
I reinstalled the HW RAID card and Windows got all freaky on me because it saw the 500MB system reserved partition and went into some sort of automated repair system. I pressed the power button down until the system shut off and I pulled the drives associated with that array. Then powered back on. Windows 10 booted up, I hot-plugged the drives, erased them from the MSM GUI, after cycling them one more time they were considered blank / good unconfigured drives. So, I recreated the array on the drives again.
I guess I'm ready to make a system backup and then start installing the various programs, tools, and software that need to be on this system.