This is a 4-disk set for installation of the MS-DOS 6.22 onto a hard disk. Disk #1 of the installer is bootable. Disk #4 is the supplemental "enhanced tools" disk. These files may be copied to your hard disk after install. This listing also includes a custom boot disk which contains CD drivers and more (see the listing for the boot disk only) Check my other listings if you need the DOS installer on 5.25" disks instead.