To run the COM Registration Fixing Tool, and this presumes NVDA is already up and running:
1. Hit NVDA+N,T,R
2. Hit Enter. You will then get the Warning dialog that you are about to run the tool and it makes registry changes, with Yes and No buttons, with Yes as default. You will, of course, choose Yes.
3. The COM Registration Fixing Tool begins, and then you will get a User Account Control (UAC) dialog asking if you want NVDA to make changes to your machine, to which you'll answer in the affirmative.
4. The tool runs and pops-up a dialog noting it's complete, which you must dismiss afterward.
5. I exit NVDA and start it again, though this is not strictly necessary.--
Brian - Windows 10 Pro, 64-Bit, Version 20H2, Build 19042
Always remember others may hate you but those who hate you don't win unless you hate them. And then you destroy yourself.
~ Richard M. Nixon