Well, I looked for doc on properly registering .OCX on Win10, and it indicated "regsvr32 iGrid460_10Tec.ocx", without the /install switch, so I tried that (as Admin), and it appeared to succeed. But still, when I ran the demo (project1.exe), it failed with the same error I originally posted. Just letting you know...
I will still proceed with trying the full 4.65 demos and VBA examples, and let you know.