@echo off
:: Test for delayed environment
set test=foo
for %%x in (1 2 3) do set test=!test!%%x
if %test%==foo123 goto OKAY
cls
echo This batch file will DELETE duplicate files in it's directory.
echo.
echo You MUST run this batch file in a delayed environment.
echo start a session like this:
echo CMD /V:ON
echo.
pause
goto DONE

:OKAY
set oldsize=0
set fnamenew=foo

for /f %%x in ('dir /os /b *.*') do call :PROC %%x
goto DONE

:PROC
set fnameold=!fnamenew!
set fnamenew=%1
for /f "tokens=3 delims= " %%x in ('dir %1 ^| find "/"') do set newsize=%%x
call :CMP "%oldsize%" "%newsize%" %1
goto DONE

:CMP
echo %2   %3
if [%1]==[%2] call :HIT
set oldsize=!newsize!
goto DONE

:HIT
fc %fnamenew% %fnameold% | find "no differences"
if not errorlevel 1 del %fnameold%
goto DONE

:DONE