GNU Privacy Guard – DIRMNGR.EXE
Dirmngr.exe installs with GnuPG, the Gnu Privacy Guard. GnuPG is the GNU project's complete and free implementation of the OpenPGP standard as defined by RFC4880. GnuPG allows you to encrypt and sign your data and communication, features a versatile key management system as well as access modules for all kind of public key directories. GnuPG, also known as GPG, is a command line tool with features for easy integration with other applications. This program is intended as a replacement for PGP. You'll find more information at http://www.gnupg.org/.
Because it is a fairly common term, there may be other programs using a file named dirmngr.exe.
Safe
Werner Koch