In this epsiode of troubleshooting, the issue is that the software basically starts, splash screen shows up and then disappears. In the event viewer, there is an exception code: 0xc0000005. This is not a very helpful error message. We even tried looking at promcon files and it didn't point to anything relevant.
One variable that helped us figure out the probelm was that that it worked as an administrator but not as a user [administrator] account. We even try to reset AutoCAD back to default.
The proverbial hail mary is to backup, then remove this key:
Once this key is removed, the software should started in the problematic account.
I would like to thank John Kaiser for sharing this tip with the community.