In lieu of multiple responses, I'll reply to Syntax Error ...
"depends what you mean by "productively""
Uh ... getting useful work done?
"DesqView and DOS 5 are so ancient I have serious problem knowing what you could with such OSs."
So why offer up an opinion?
"You would certainly have a problem using the internet"
No. I was using TehIntraWebTubes[1] before Microsoft existed ...
"unless you just like text."
That's a problem in your mind? 99% of the useful content available online is text. Seriously, think about it ...
"I don't think there is a web browser"
There was (and is); it's called "lynx" ... Once HTTP became common, anyway. Prior to that, we used telnet and ftp, for the most part.
"You would only be able to connect to the internet via SLIP or PPP."
Today, I use a modem to connect to TehIntraWebTubes[1] about one week a month, at 9600 baud on a good day. Most days it's more like 2400 or 1200. Fort Bragg, CA weather & an ailing cable plant make for a piss-poor signal/noise ratio.
"I doubt you could record sound."
Yes, I could record & edit sound. In stereo, even.
"Printing colour would be very difficult."
CMYK dot matrix printers were available.
"Inserting pictures into text documents? Possible but not easy."
PageMaker made that almost laughable easy.
"Creating web pages would be tricky. No web browser."
The WWW was very young in this time-frame. It was pretty much all text (kinda like Gopher). Everything was created using a text editor. And guess what? All of those pages are STILL readable (if they still exist). Unlike some stuff created with so-called "modern"' software that exists to lock consumers into corporate advertising bullshit, thus locking out people who refuse to conform.
"You wouldn't be able to make a powerpoint presentation."
Cry me a river. As a consultant who is brought in to fix b0rken c0rporate c0mputing, one of the first things I do is fire the middle management who claim (on a survey I provide) to "rely on powerpoint". Powerpoint has wasted more meeting hours ($$$) than any other bit of corporate bullshit that I can think of ... That said, read up on "Aldus Persuasion".
"Ask any Secretary"
Ask any secretary who worked with a Displaywriter if a current Microsoft-based system is better. But get ready to duck, you'll probably get slapped.
"Your whole set up sounds eccentric."
Ta :-)
"You cannot enjoy the pleasures of 21st century web browsing"
Yes, I can. My main box is Slack-current. Horses for courses and all that.
"video"
I have dedicated video gear. Including production.
"music"
I have a dedicated sound system. Including production.
"and other what you call non-productive tasks"
Are they productive, or entertainment? If entertainment, are they really required at work?
"but then maybe you don't want to"
I don't think you really grasp my point ...
"Windows7 is a lot more useful than DOS"
Post proof, or stop regurgitating Microsoft's marketing babble.
"and a lot more fun!!"
Ah. Glitter rules, then. Sorry, bub, I use these tools to make a living ...