Reorder folders by Letter (first letter)

@echo off
setlocal enabledelayedexpansion

tree
for /d %%i in (*) do (
  set first=%%i
  set first=!first:~0,1!
  md !first! 2>nul
  if not "!first!" == "%%i" move "%%i" "!first!\%%i"
)
tree