Error: Windows version vs. Bluetooth API

I have always used Anki on Windows 8.1. But I haven’t used Anki for a while. Now, it stopped working.
Every new install v2.1.43, v2.1.40, v2.135 can install but fails to open afterwards with error message:
“This Windows version (6.2.9200) does not support the required Bluetooth API. consider updating to a more recent Windows (10.0.10586 or above).”
Any idea? - apart from going to Windows 10.

Maybe removing the c:\program files\anki folder and then installing again will help.