Most computers made in the early 1990s had a version of Windows 3.1 running on top of DOS. It was said that Microsoft let computer manufacturers install copies of Windows cheaply as long as they did not bundle OS/2 with it or pay full price.
VirtualBox Guest Addtions status: Officially No but somewhere there exist some DOS additions I need to look for and publish the instructions.
Here are some screenshots:
There were other shells besides Progman.exe that could run your desktop. One was Calmira which is a Windows 95ish desktop for Windows 3.1x
OSCollector 