The packages within the MinGW/Extension directory are supported by the
MinGW development team; they provide useful facilities, but they are not
considered essential for a basic MinGW installation.
To install files distributed by MinGW we suggest you use the mingw-get
installer: https://sourceforge.net/projects/mingw/files/Installer
To set mingw-get up for first time use, run the mingw-get-setup.exe
tool; this will install mingw-get for use as a command line tool, and,
at your option, as a GUI installer tool. Once set up, you may then use
it at any time, to install your choice of additional packages.