I run Windows for WorkGroups on a Dos 6.22 Virtual Hard disk under Windows 7. I can even get on the internet with it.
Why, you ask, Because...
I had to install DOS on the Virtual hard disk first and when it came up and asked me to format the C drive, I did get a bit nervous. Then dos installed fine. Installing windows was a bit tricky as you have to have several drivers from different internet sites before it will use TCP/IP.
But I periodically put it in full screen mode and show people that I can run dos/win on my laptop.
I have several Virtual Hard drives with Dos, Windows 98, W2K, XP and Ubuntu which all work. There are some wierd things you have to do to get them working correctly but they do work.