Fix a windows doc issue

Signed-off-by: evalle <shmarnev@gmail.com>

docs/installation/windows.md

@@ -346,7 +346,8 @@ uses. You can do this with
 [puttygen](http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html):
 
 1. Open `puttygen.exe` and load ("File"->"Load" menu) the private key from
-  `%USERPROFILE%\.ssh\id_boot2docker`
+  
+        %USERPROFILE%\.docker\machine\machines\<name_of_your_machine>
 
 2. Click "Save Private Key".