REM -------------------------------------------------------------------------------             REM On System Drive, the files DRIVE-.? indicate letters not to be assigned             REM ------------------------------------------------------------------------------- =>         FOR %%U IN (!TMP_OLD_LETTER!:\DRIVE-.?) DO (                 SET TMP_NOT_FREE=%%~xU                 SET TMP_FREE_LETTER-!TMP_NOT_FREE:~1!=             ) I can verify that is code does in fact fix the problem with free letters not be reserved.