Notes about the GPG file extension:
Incorrect file associations could be the result of underlying issues within your PC system. As such it is highly recommended to scan your PC for invalid registry entries
, unused processes and other unfavourable system settings to identify slowdown issues.
The GPG file type is primarily associated with 'GNU Privacy Guard (GnuPG)' by Free Software Foundation, Inc.. GnuPG itself is a command line tool without any graphical stuff. It is the crypto engine which can be used directly from a command prompt, from shell scripts or by other programs. Therefore it can be considered as a backend for other applications. It is a full OpenPGP implementation (see RFC2440).