Why?
Well, seeing as you asked...
Mainly because I am tight. and proud.
I use DOS when I want to get basic work done and don't want to lose processing power to a graphic interface,
I had acquired a number of very specialist programs that run on 3.1 and to replace them would cost thousands and I don't want then THAT much! Including a star map that runs like blazes on a 3GHz processor
I actually wrote some programs for 3.1 and they worked. I can't be bothered to learn all over to do that again.
I have a wonderful collection of avionic simulator stuff that runs on 98SE and a lot of games and stuff I don't want to lose.
And various bits 'n' bobs from 2k that won't run on XP and so on.
I have been running a evaluation copy of Vista for getting on a year and it should have collapsed on June 1st and it didn't
Finally I have documents and programs I created on a BBC-B that I still refer to and one of the best collection of Arcade games ever seen. but I corrupted my ELITE
(5 1/4" Floppy disks are getting on a bit) and I cannot find a replacement, the PC versions weren't half as good
I have a world standard score on "Swoop"
.
The best of it all is that when I have finished with the virtual machines they just disappear they, don't collect dust or sink under other stuff, and are always available at a click.
OK?