Delete old Window Display Language after upgrading WIndows 10 Home SL to Windows 10 Pro

Question

I upgraded my account license to Windows 10 Pro from a Windows 10 Home Single Language GB version. I want to completely remove GB (British English) from my Display Languages but I can not do so.

I changed to US English as the display language and added English with German keyboard layout as an alternative layout because I need to switch between the 2 layouts. Whenever I use hotkeys to change languages (and keyboard layouts) between US English and German (the two languages I set up in settings) there will always be GB in between. And even after setting US English as my Default Display Language in settings it will STILL show GB as an option in the language toolbar...

Even in an elevated power shell using Set-WinUserLanguageList with -Force parameter it will achieve nothing.

GB always stays selectable in display languages inside language settings and the languages toolbar...

The "Windows Display Language" dropdown in my settings contains:

English (United States)
English (United Kingdom)
English (Germany)

The "Preferred Languages" section contains:

English (Germany)
English (United States)

I tried adding English (United Kingdom) to preferred languages and deleting it afterwards as well, but it did not remove it from Windows display languages either.

Answer 1

I followed one link posted by @Andrew Morton in the comments.

I tried most of the suggested methods even before posting, but the only thing that worked for me out of the new additional ways mentioned there was editing the InstallLanguage registry key.

Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Nls\Language

The key value should be the last 4 digits of the Keyboard identifier.

Registry Editor InstallLanguage key Screenshot

After rebooting the en-GB keyboard and display language was finally gone.