AI: win7 v.23.03. Win8.1 v.22.1

I've researched this problem. I've read that it's recommended to update to a newer version of windows to overcome it.

I get the latest version of Illustrator CC 23.0.3 on my Windows 7 main computer but on my Windows 8.1 portable computer I can't update Illustrator beyond version 22.1

I've read of the various fixes for "Available updates not listed" and applied them but still got the problem.

TonyH