For me M-x org-display-inline-images didn't work on windows. The error I get is: "No images to display inline"
Googling gave me this, but that didn't really help...
Eventually the README in the Emacs downloads folder was more helpful:
Emacs can also support some other image formats with appropriate
libraries. These libraries are all available on the following sites:
1. http://sourceforge.net/projects/ezwinports/files/
-- leaner, more up-to-date builds, only for 32-bit Emacs
2. http://www.gtk.org/download/win32.php
http://www.gtk.org/download/win64.php
-- the GTK project site; offers much fatter builds, but includes
64-bit DLLs (from the 2nd URL)
3. GnuWin32 project -- very old builds, not recommended
So in order to view inline images you should get the ezwinports of libpng, giflib, jpeg and librsvg
Unzip these files and add the directories to PATH. After this, org-display-inline-images seemd to work for me.
Tested with Emacs 24.5, org-mode 8.3.3 on windows 7.
Hope this saves somebody some time.