gunzip problem on Windows

[Xah Lee <xahlee@gmail.com>]

when using emacs on Windows, when in dired, when i press Z on a file
that's gzip compressed, emacs tells me:
'gunzip' is not recognized as an internal or external command,

the problem is apparently that emacs won't recognize the gunzip shell
script without the exe suffix. (the gunzip is in the same dir as
gzip.exe) But if i rename gunzip to gunzip.exe, but Windows complain
that the file is not a exe format.

How to solve this problem?

extra detail:

when i do
(executable-find "gzip")
emacs says
"c:/cygwin/bin/gzip.exe"

and
(executable-find "gunzip")
says
nil.

the gunzip exists at
c:/cygwin/bin/gunzip
which is a shell script.

  Xah
∑ http://xahlee.org/

☄