problem installing Windows 3.1(3.x) on Microsoft virtual machine

The point that people are making, although maybe not very explicitly, is that MS-DOS is not freeware. Neither are old versions of Windows. They are copyrighted Microsoft products, and because of this you need to get them legally. A full install set of Windows 3.1 includes an MS-DOS 6.22 full install set, does it not? So what are these disks you have?

A full install set of Windows 3.1 includes an MS-DOS 6.22 full install set, does it not?

No, Windows 3.1 didn't include any version of DOS; it had 7 disks and a manual.

the box should have said "DOS sold separately"

You SHOULD be able to run Windows 3.1 under FreeDos (A free equivalent to MS-DOS)

Freedos: http://www.freedos.org/

No, Windows 3.1 didn't include any version of DOS; it had 7 disks and a manual.

the box should have said "DOS sold separately"

I think I was getting confused because the Compaq I bought in 1993 came with both install sets.