recompress

@ECHO OFF
REM zip_to_7zip_subfolders.bat - find all .zip, .rar and 7z files in the current directory and all subfolders, recompress them into zip files - but don't delete the originals.
set RootDir=%CD%
set OutputDir="d:\TMP\try\SomeFolder"
set ArchiverDir="e:\Program Files\7-Zip\7z"

ECHO Searching for RAR and ZIP files to recompress into 7zip archives.
for /R "%RootDir%" %%F in (*.rar *.zip *.7z) do (
    ECHO Found %%F to recompress...
    REM Extract...
    %ArchiverDir% x "%%F" -o"%TEMP%\_manga\%%F contents"
    REM Does the directory exist? has 7zip created it correctly?
    IF EXIST "%%~fF contents" (
        REM Change directory, create 7zip of contents of directory...
        CD "%%~fF contents"
        %ArchiverDir% a -t7z "%OutputDir%\%%~nF.7z" * -mx=9
        CD "%RootDir%"
        REM Delete the temporary extraction folder
        RMDIR "%TEMP%\_manga\%%~fF contents" /S /Q
        ECHO Recompressed %%F to %%~nF.7z
    )
)

ECHO Search ended.