[Foreigner]

kelevara,
можно просто dir-ом:

Код:

@echo off
setlocal enabledelayedexpansion

set size=0

for /f "delims=" %%i in (' dir /b /s "c:\lab1\wingraf\*.gif" ') do (

    if %%~zi geq !size! set "file=%%~fi" && set size=%%~zi

)

echo %size% "%file%"