I am replying to my own message. At some point it occurred to me to try running the AMD driver set as administrator. It worked! I have never had to run a driver set as administrator before but my Windows is Windows 19 Pro, 64 bits. I got a deal on the license key. It has been years since I have run a "Pro" version of Windows so I don't remember if it is usual to have to run driver installation as administrator. My problem now is that no subsequent driver set has run correctly, even as administrator, so I am still running version 17.9.3. And Windows Update now fails. So the recent major update is marked as "failed" when I check my update history. I toyed with the idea of buying an NVIDIA card and giving up on AMD but this is the most expensive graphics card I have ever bought and I couldn't make myself turn it into a paperweight. It looks like the NVIDIA Geforce GTX 1070 ti is equivalent in power and at least on "Cyber Monday" cost slightly less than my Vega 56. I wish I could find someone who is successfully running the Vega 56 on a Gigabyte motherboard so I could know that what I am trying to do is not impossible. I found several cries of pain on the web about the Vega cards, always on Gigabyte motherboards.