If the computer has really old hardware that's easily achievable. The trick is to get any current hardware to run on such old OSes because the hardware manufacturers no longer make drivers for the old OS versions 
You are limiting yourself to the manufacturers themselves concerning drivers much like you limited yourself in that "markmonitor" comment on another thread.........which you obviously abandoned when you finally got around to checking and found I was right.
There are plenty of drivers out there for most any hardware configuration......but you have to look.......they won't magically float onto your hard drive and you sometimes have to write your own way to get it onto your computer.
Hell.....I even run games that need the dos4gw extender on current hardware and modern OS's.
One of the tricks for that is to keep your path statement as short as possible and to set up a dos environment using virtual IRQs, IO, and DMA.
If you trace my motherboard ownership history you find systems such as
486DX50.......full DX 50mhz bus....not a dx-2 and I even found a VLB video card that successfully ran at the full bus speed.
Iwill P55tu running a pentium mmx 200 with aic7880 ultra wide scsi and the optional adaptec ARO1130 raid controller, has two sound cards in it, an ati 3dpro-turbo+pc to tv with 8mb of sgram along with the optional tv tuner card.
This allowed me to play the latest games, mix multiple channels of music, play a hardware synth with 32 megs of sample ram, capture video, output video to tv, and watch tv on the computer as well as record CDs (in 1995) with the philips cdd2000............I still have it and it still runs though most (not all) of the scsi drives and the cdd2000 have died so I no longer record cds with it but I did use it the other day to use with a midi keyboard and output spdif to a mixer.
At the time, I was supporting a software package that required up to 38 CDroms which I mounted on the scsi hard drives and I had 5 external drives in cases.......some of which I still use with an old fostex digital 4 channel recorder instead of the computer.
ABIT KT7A raid.......only recently died but I ran three sound cards, tv tuner and capture, and the old and reliable awe32 with 32 megs of sample ram onboard for zero latency.....not low latency....but zero latency just like in the pentium I above.
I don't run dos3 on my latest computer because I don't need to but I can run every microsoft OS from early dos versions to the latest windows on a KT7A raid and have full ISA bus functionality unlike the "quasi isa" as found on my current ADEK I7 processor motherboard.
If you have the will, you will find a way to get the functionality you want out of your hardware and most of my systems are mixing parts listed as incompatible with each other.......which I found is mostly BS from frustrated owners.
There was a lot of trial and error in the system examples above but I did the legwork myself and made more than my share of custom .inf files that pointed to drivers not intended for the hardware but that I found would work.
What I got was functionality far beyond the standard.
What I am saying, ripley, is that you can't make a blanket statement about compatibility or value of what I have done with my various OS's over the years without having traveled a similar path as mine.
I've long ago moved away from staying on the cutting edge of "personal computing" and now customize engine management systems for cars but that knowledge and ability remains in my head without the need for internet research to make a point.
Actually, the default mode for all Intel based motherboards has been consistent since the 80386 was introduced. Not too hard to believe those old operating systems would run. It would not be pretty due to the lack of native drivers for the video card (VGA mode still works). No sound would available either, unless you had a really old Creative card in the computer.
The rest has pretty much stayed the same (set the SATA ports to run IDE mode) and I could see those old operating systems working,...not well,..but working.
It is true that intel processors are extremely similar going way back and I feel they are still wringing all they can from the basic architecture originally shown in the pentium pro though I think there was a good leap when the pentium M showed how to get more with less as opposed to the pentium 4.
Yes skuzzy, I do run a very old creative soundcard in the kt7a raid and the old Iwill p55tu that has onboard memory........and it works for every modern OS I've tried but I haven't tried windows 8 on it.
Hell....I even have a choice of asio or wdm drivers.
I don't run it on the newest ADEK I7 based system even though it has an isa slot because the new systems have a DMA issue with the ISA slot so I fear that path has finally closed for many interface cards with isa interface.
