to remove the "QAA Unknown Locale (qaa-Latn)" language from the list of languages in Windows 10, is to reset the Windows display language to default settings:

1. Open PowerShell with Administrator permissions. To do that:

1. 
   
   1. At Cortana‘s search box, type powershell
   2. Right click on Windows PowerShell result and select Run as administrator.

2. Give the following command to get a list of the installed languages and to view the LanguageTag for each installed language:

• Get-WinUserLanguageList 

• $LanguageList = Get-WinUserLanguageList

• $LanguagelList.Add("qaa-latn")

• set-winuserlanguagelist $LanguagelList -Force

3.Now, remove QAA-Latin