I have installed the latest available WINDOWS Kontact/KMail (K3-Kontact-Beta-2013-07-05) AND:
1) The latest available GnuPG for WINDOWS (GPG4win 2.2.2) and Kleopatra "Self-Test" produces:
1) GPG (OpenPGP Backend) installation "not supported" ... Seems to object to GPGME?
2) GpgSM (S/MIME Backend) installation "too old"
3) GpgConf (Configuration) installation "too old"
2) The latest available "Classic" GnuPG (2.0.22?) for WINDOWS (gnu-w32cli-1.4.18)
and Kleopatra "Self-Test" prodces:
1) GPG (OpenPGP Backend) installation "not properly installed" ...
Recommended enter: "gpg --version" which gave:
gpg <GnuPG> 2.0.22 <Gpg4win 3.9.1git2-pkg43>
libgcrypt 1.5.3
2) GpgSM (S/MIME Backend) installation "not supported"
Recommended: "Replace the gpgme library with
a version compiled with gpgsm support.
3) GpgConf (Configuration) installation "not supported"
Recommended: "Replace the gpgme library with
a version compiled with gpgconf support.
I updated the PATH Environment Variable so that isn't the problem.
Claws Mail encryption/decryption works just fine.
Thunderbird/Enigmail encryption/decryption works just fine
There is no "Backends" TAB when I click on "Security".

Is there some "undocumented" step necessary to get this working?
Is there some available WINDOWS GnuPG version that does work with KMail?

Thank you,

This is a very old version. You may want to look for Kontact version 5 for Windows. Otherwise, if you really need this version, best is to enquire directly from where you downloaded from (which they're the people supporting it).

If you could please point me to where I can download "the latest" Kontact for Windows, I would appreciate it. I have been rummaging around for days without success. And, I have been no more successful in locating a "Kontact Version 5 for Windows"). All I find is old/obsolete webpages/packages.

This is the latest link I could find:

http://mirror.kolabsys.com/pub/upload/windows/

Thank you Salvor Hardin. That is where I found "Kontact/KMail (K3-Kontact-Beta-2013-07-05)". It appears that "Kontact for Windows" porting has stopped. That is unfortunate because there are features of Kontact in which I was interested that are lacking in Claws Mail and Thunderbird/Enigmail.