All DOS (MSDOS) up to and INCLUDING MS-DOS 6.22 need IO.SYS as first file and MSDOS.SYS as second. Starting from MS-DOS 7.0 (Windows 95) this is not needed anymore. In a nutshell the bootsector code was changed in 7.0 and could access IO.SYS no matter where in Root Entries it was, whilst previous DOS versions needed both IO.SYS and MSDOS.SYS as first root entries. (and only IO.SYS is used, MSDOS.SYS having become a ".ini" file) http://the