IBM OS/2 Warp:
(also works with OS/2 2.x - untested with 1.30 Extended Edition)
1. Open the install (disk 0) img dump and drag the os2krnli file to the desktop.
2. Open os2krnli with notepad (or textedit if on a mac).
3. Do a search for "Internal revision". Next to that phrase is the revision/build number.

Most of the recent (ie 2.1 and later) OS/2 versions give the build on ver /r at the command prompt.

Note the cmd line for vers a.b gives 2.ab.1234 where 1234 is the OS level.

Take command/os2 gives OS/2 Warp Connect as 3.1, and since there is an OS/2 Warp, i use 3.1 to refer to the latter build.

Regarding DOS.

MS-DOS generally returns the value from the interrupt, as jj.mm (major-minor). Some exceptions apply

msdos 6.21 returns jj.21
msdos 7.xx and later return a string embedded in command.com, eg 4.10.2222. You can edit this yourself.
ntdos returns jj.mm.500, where jj.mm is the underlying DOS version.

PC-DOS from 6.0 returns a string embedded in command.com.
os2 dos returns 2.jm but answers to 20.jm to a DOSVER interrupt test.

You are better to run some third-party utility that intercepts the underlying interrupts, rather than reading command.com.

Winver returns a windows version, as does shell.dll (eg notepad -> help|about ). I've seen non-released versions here, eg WinOS2 3.11 (ie from the winos2 shell.dll running on top of windows 3.11).

Linux (Kernel Version):

Open a terminal, and enter the command:



The resulting output will be the version of the Linux kernel used on the system.

MS-DOS and PC-DOS. xx.yy

"ver" generally returns the dos version. Some differences are known.

DOS 4.01 returns xx.(yy+1)
MS-DOS 6.21 returns xx.21
WinNT DOS returns xx.yy.500 (where xx.yy is typically 5.50)

PC-DOS 6.x and later returns a string embedded in COMMAND.COM
DOS95 returns a string embedded late in COMMAND.COM

These dos versions differ from the box-name. Command,com reports the version from a string in the exe file.
DOS 4.01 is actually 4.00
PC-DOS 6.10 is actually 6.00
MS-DOS 6.21 is actually 6.00
OS/2 DOS reports 20.xy where x.y is the OS/2 version. vers 1.x reports 10.xy.
DR-DOS returns the emulated DOS, but this is the default OSVER variable. Internally it uses a different build number.

MSD or 4DOS reports the dos by int30 call etc.

For Windows Vista and above, won't "slmgr.vbs /dlv" work?

It does work with OS/2 1.3x, however, the build number sequence is a bit odd.

For 1.30.x the build numbers seem to be 7.2xx

For 2.xx the build numbers seem to be 6.3xx

For 3.x the build numbers seem to be 8.xxx

There is no internal revision comment in OS/2 1.1x or OS/2 1.2x.

for OpenVMS, the command is


Some more details can be seen during boot:


From 7.3 onward, additional layered products and their versions can be seen by


Edit: Bruce Hamilton's UNIX Rosetta Stone Website might also be helpful for some...