I ran Steps 1, 2 and 3 from the Microsoft link.
Step 1. Went to Add/Remove Programs. Easy Roxio CD Creator is not shown as being installed. I uninstalled it about 6 years ago.
Step 2. Checked value for AutoRun in HKEY\...Services\CDRom. It was 1 which is what the link said it should be.
Checked value for NoDriveTypeAutoRun in HKEY\...Policies\Explorer. It was 91 which is what the link said it should be.
Step 3. Checked value for allocatecdroms in HKEY\...Current Version\Winlogon. It was 0 which is what the link said it should be.
Personally, I would prefer if the problem could be identified and solved, rather than using Acronis to restore the C:\ drive to an image from March 2012 or doing a Windows XP repair, but nonetheless, this is frustrating. The problem exists, so the cause is hiding inside my case somewhere!