Search notes:

%PROGRAMFILES%\WindowsApps

WindowsApps is a hidden folder where Windows 10 keeps installed apps from the Store.
In contrast, so called System apps are installed under %SystemRoot%\*.
The value of the Environment Variable %PROGRAMFILES% is typically C:\Program Files, thus the WindowsApps directory is located in C:\Program Files\WindowsApps.

TODO

In PowerShell: 
get-appxPackage | select-object name

See also

Windows 10: types of apps
Windows apps
The parent directory C:\Program Files

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