it was well known a few years ago, but anyway this is from the script itself (search for the "bin64") Code: if not defined _wimlib ( if exist "wimlib-imagex.exe" set _wimlib="!_work!\wimlib-imagex.exe" if exist "bin\wimlib-imagex.exe" set _wimlib="!_work!\bin\wimlib-imagex.exe" if /i %xOS%==amd64 if exist "bin\bin64\wimlib-imagex.exe" set _wimlib="!_work!\bin\bin64\wimlib-imagex.exe" )