Windows 10: Install .Net 3.5 offline from installation media

@echo off

:: SOURCE: https://winaero.com/blog/offline-install-of-net-framework-3-5-in-windows-10-using-dism/
::
:: USAGE: Plug your Windows 10 USB stick in (or mount the Windows 10 .iso file) and run this script with admin privileges.
::        It will search for the install media and install .Net 3.5 from it.
::
:: NOTE: The reason for this script is because "dotnetfx35.exe", the official offline installer for .Net 3.5, still requires internet access.

:CheckPermissions
    setlocal

    fltmc >nul 2>&1 && (
        goto :Work
    ) || (
        echo Error: This script requires administrator privileges.
        echo.
        echo Right click this scripts icon and select "Run as Administrator".
        echo.

        goto :End
    )

    endlocal & goto :eof

:Work
    Title .NET Framework 3.5 Offline Installer

    for %%I in (D E F G H I J K L M N O P Q R S T U V W X Y Z) do if exist "%%I:\\sources\install.wim" set setupdrv=%%I

    if defined setupdrv (
        echo Found installation media on drive %setupdrv%
        echo.
        echo Installing .Net Framework 3.5...
        Dism /online /enable-feature /featurename:NetFX3 /All /Source:%setupdrv%:\sources\sxs /LimitAccess
        echo.
        echo .Net Framework 3.5 installation complete...
        echo.
    ) else (
        echo No installation media found!
        echo Insert DVD or USB flash drive and run this file once again.
        echo.
    )

:End
    pause