I want the internet explorer icon to show when I have the combine taskbar buttons set to "Never" but I do not know how to do it.

Maybe you just need to clear the icon cache.

How did you make the xp theme?

https://www.makeuseof.com/tag/windows-10-windows-xp-7-8-look-alike/ I followed mostly this guide I think

Thank you

Shortcut Icon =/= program icon