I've ran Windows 3.1 in DOSBox before. I can't say it was a fun experience, it's not very stable. Trying to use The Way Things Work, a multimedia CD-ROM from Dorling Kindersley, would crash it occasionally.
If you want to run old Windows, I suggest a proper virtual machine.
It's hard to get networking functional inside DosBox, but works pretty well beyond that. I use this for some old Windows games (Castle of the Winds etc) and other nostalgiaware (Visual Basic, AmiPro etc). :)