Emacs找不到plink

Question

我正在运行emacs 24，我想在我的ubuntu机器上设置tramp来读/写文件。

我读了emacs 24 on windows 7, tramp cannot find plink program。我确实打印了exec路径，我的exec路径中有C：/ Programs / Putty：

exec-path is a variable defined in `C source code'.
Its value is
("C:/Programs/PuTTy" .....)

但我还是得到了

plink -load 10.136.11.77 -t env 'TERM=dumb' 'PROMPT_COMMAND=' 'PS1=#$ ' /bin/sh && exit || exit
plink is not recognized as an internal or external command, operable program or batch file.

我的.emacs中有这个：

(require 'tramp)

(require 'package)
(add-to-list 'package-archives
             '("melpa" . "http://melpa.milkbox.net/packages/") t)


(add-to-list 'exec-path "C:/Programs/PuTTy")
(if (eq system-type 'windows-nt)
    (setq tramp-default-method "plinkx"))

任何想法如何解决我的问题？