What to do with the tarball now?
Untar it via ‘tar xvzf gnus.tar.gz’ and do the common ‘./configure; make; make install’ circle. (under MS-Windows either get the Cygwin environment from http://www.cygwin.com which allows you to do what's described above or unpack the tarball with some packer (e.g., Winace from http://www.winace.com) and use the batch-file make.bat included in the tarball to install Gnus.) If you don't want to (or aren't allowed to) install Gnus system-wide, you can install it in your home directory and add the following lines to your ~/.xemacs/init.el or ~/.emacs:
(add-to-list 'load-path "/path/to/gnus/lisp") (if (featurep 'xemacs) (add-to-list 'Info-directory-list "/path/to/gnus/texi/") (add-to-list 'Info-default-directory-list "/path/to/gnus/texi/"))
Make sure that you don't have any Gnus related stuff before this line, on MS Windows use something like "C:/path/to/lisp" (yes, "/").