MS-DOS 8.00
From BetaArchive Wiki
MS-DOS 8.00 was never released as a seperate entity. It was only found on the Windows Millenium Edition OS, witch was released in 2000. A bootdisk image was found in diskcopy.dll Windows XP/Vista/7 & was found to be a modifed version of the Windows ME Bootdisk
It is the last version of MS-DOS ever created.