A. The easiest way I've found is to download the MS-DOS 6.22 boot ISO and boot the VM from it. If you're using Hyper-V, you could also use virtual floppy disks and boot from the MS-DOS install disks, but this isn't an option for Windows Virtual PC. Follow these instructions to copy DOS from the ISO to the virtual hard disk.

Start fdisk and create a new primary partition. Once created, reboot the machine and format the new partition as a system partition using the command

format c: /s

Now copy over the content:

C:
MD MSDOS
COPY A:\*.* .\MSDOS /v
COPY A:\CONFIG.SYS
COPY A:\AUTOEXEC.BAT
COPY A:\HIMEM.SYS
COPY A:\CD1.SYS

You'll now be able to reboot to DOS in your VM. If you're running Virtual PC or Windows Virtual PC, you can even add Windows for Workgroups for a real old-school feel.

Related Reading:

Check out hundreds more useful Q&As like this in John Savill's FAQ for Windows. Also, watch instructional videos made by John at ITTV.net.