I also skipped version 4 but, as I recall, the two main reasons was that it used more conventional memory (which was quite a critical factor those days) and that it was (initially) quite buggy.

Is it? I guess more conventional memory would be the only reason I might ever use anything older than 6.22 now. 5.0 was my first version, so not much nostalgia there.

Not sure my understanding of your comment is correct but, bear in mind that, back in those days, all DOS applications had to be loaded within the first 640k of RAM.
Most users still had XT PC's (which was limited to 640k RAM) and, for those that could afford a 286, having more than 1 MB of RAM was a novelty (memory was very expensive).
If your operating system took up too much of that conventional memory, then some applications would simply refuse to run.

I started out with DOS 3.2 (on an Olivetti M19) but later upgraded to DOS 5.0, which I found was a nice fit for an XT class PC. Many people also like to go with DOS 3.3 and this was very much the version that most people stuck with until version 5 came out.

It had some advantages over previous DOS, but also some questionable decisions. Remember that (at least in my country) when it was launched most installed computers were 8086 and 80286 with 20 or 30Mb hard disks.

The good things:

- It supported partitions bigger than 32 Mb, so it was (almost) needed to use newer 40 Mb HDDs (but you could still split your HDD in two partitions to keep them under the 32 Mb limit).
- Introduced some memory managers into DOS.
- Introduced DOSSHELL, a text UI that help users to do things without using the command prompt. It even could run more than one DOS program at the same time and switch betweem them.

The bad things:
- The memory footprint was bigger than any DOS 3.x, so some programs needed tweaks to run.
- The memory management was not as advanced as in later DOS (i.e.: you could not get advantage of HMA) and most stuff was propietary (it worked only on some brands and models of computers). You still needed hardware support and/or propietary drivers for EMS (=no EMM386).
- DOSSHELL was not practical. It left less memory for DOS programs, some programs (mostly games) couldn't be switched and switching between programs was sloooow. The worst thing is that the installer made DOSSHELL run at every boot by default.

So, as you discovered, MS-DOS 4 faded into oblivion. Most 8086 users reverted (or never left) to MS-DOS 3.x because it was better suited for their machines (more free memory) and 386 users got into MS-DOS 5 because the more advanced memory management (EMM386, HMA, UMB and those things). I don't know what 286 users did... I guess most stuck on DOS 4 (after disabling DOSSHELL), but I'm not sure.

DOSSHELL was still included on DOS 5, but in DOS 6 it was moved to the "supplementary disk" so most people forgot that it even existed. By the time that DOSSHELL became usable (because CPU performance and RAM available), there were more and better shells for DOS in the market (but they were not free). Also, Windows 3.x did everything DOSSHELL could do, and their programs were more intuitive than DOS programs.

The problem with DOS 4.0 is that it was an IBM-only development. Unlike Microsoft, IBM didn't care much about good code back then, which is why 4.00 was so buggy that it was rewritten by MS and silently released as 4.01 by IBM (same box, disk labels etc. You can't tell until installing). Wikipedia wrongly states that there was no IBM PC-DOS 4.01, btw.

To add to the confusion, there was an earlier MS-DOS 4.0, which was a multitasking version of 2.0 done by MS in 1986.

I cant say anything about why it was and is disliked.... Though I can say what I remember from the time when it was released. What I remember, is that no one liked it back then and everyone switched to 5.0 as soon as it was released.

I installed the version 4.01 (so the glitch-less version) on my 286 because that's the only DOS I have boxed, and it's not that bad actually, it's really in between DOS 3 and 5. It feels more like DOS 3 though.

Maybe it didn't change enough while having the "buggy OS" image in people's mind so most people skipped it.

It's a bit like Windows Vista I guess. With updates it was mostly fixed, but in the meantime Windows 7 was released so people stayed on XP until Windows 7 came out and thus skipped entirely Vista.

Deksor wrote:

Maybe it didn't change enough while having the "buggy OS" image in people's mind so most people skipped.

There's more. DOS 5/6 do use the same kernal structures as DOS 3.x again.
DOS 4 was different. It tried to introduce some improvements the world wasn't ready for.

For example, an installable filesystem (IFS) which took too much conventional memory to be useful.
On top of that, available programs of the time used features that were too tightly bound to DOS 3.

Edit: It is comparable to the Winamp history.
Version 5 went back to the Winamp 2 code base, because the users felt that Winamp 3 was to bloated.
http://en.wikipedia.org/wiki/Winamp#Winamp3

I recall the first Toshiba T3100 my family got (Not the one currently in my collection) came with DOS 4.01 when we bought it used in the 90s. I don't know if that's what it originally shipped from the factory with or not, but it's what it had when we got it, and for the limited purposes we bought it for (My mother's braille transcribing) it worked just fine.

I never used 4.0. I had 3.2 on my Tandy 286 and eventually went to 5.0 on a 486. I was told 4.0 was to be avoided because of the bugs.

I like the Windows Vista comparison.

i remember trying to use DOS 4.0 but i was quickly found that some of existing programs that i have, complained about incorrect dos version,
i believe Microsoft finally remedied that with MS-DOS 5's 'setver'.

Here is a in-depth analysis of it:
http://www.os2museum.com/wp/dos/dos-4-0/

It was the first DOS version not designed with XTs in mind and, although it can be installed on floppies, it actually requires a HDD to be useful.

I use PC DOS 4.0(1) on my 286 and MS-DOS 4.01 on a 386sx. It only needs about 5/10 (with share) KB more than 3.31 (with also has >32MB part. support). It gave me problems with one (obscure) network redirector that refused to work. Other than that is like any other DOS version. I like a lot the Vista simil. Vista is the 4th issue of Windows NT, BTW.

In summary it does not bring nothing really new or useful, XT-clones were still selling in high numbers and the first PC DOS issue had some prominent bugs so most people stayed with version 3.3

I wonder how the acceptance of DOS 4 or DOS 4/V was on the japanese market.
Wasn't four considered an -errm- not so good number ?
https://en.wikipedia.org/wiki/4#Other