http://sgur.posterous.com/quickrunvimwindowscmdexeshellset-shellslash

patch_for_autoload_quickrun.vim

@@ -577,10 +577,13 @@ function! s:Runner.build_command(tmpl)  " {{{2
   " TODO: Add rules.
   " FIXME: Possibility to be multiple expanded.
   let config = self.config
   let shebang = self.detect_shebang()
   let src = string(self.source_name)
+  if s:is_win && &shellslash && match(&shell, 'sh') < 0 
+	  let src = substitute(src, '/', '\\', 'g')
+  endif
   let rule = [
   \  ['c', shebang != '' ? string(shebang) : 'config.command'],
   \  ['s', src], ['S', src],
   \  ['a', 'config.args'],
   \  ['\%', string('%')],