Cygwin emacs-w32 with Administrator privileges
With modern Windows privileges schema (unlike in Windows XP) Emacs can't save edits to many of files
placed in special directories (like "Program Files"). To allow saving of modification you should
grand Administrator privileges to Emacs process.
Emacs 25 under Windows
I haven't used Windows for a long time and new job may require Windows environment. So I checked out
new ways to use Emacs under Windows.