I have been able to install Emacs 25.1 and AUCTeX 11.89.6 (this is the number that I have after installing it with MELPA directly from Emacs) that I am using on a Windows 7 machine. I am trying to use ispell possibly with flyspell but when I type M-x flyspell-mode I get: Error enabling flysepll (Searching for program No such file or directory ispell) I have tryied adding (require 'ispell) (setq ispell-program-name "ispell") and (setq ispell-program-name "tex-ispell") I have read that ispell comes with Emacs 25 and I have found isepll.el in the emacs directory. I have also checked that I have that directory on the Emacs path by C-h v load-path Finally, I have tried to "launch" directly from with emacs in the customization menu but failed. It seems like an easy task but I am not being able to make it work. Any pointer would be great. Thank you.