can't invoke browser

[pinggit]

when I type b on the gist list, nothing happens... I did use below command but nothing works.
any idea?

• 'b' will open the selected gist file in a browser. If you are in
  GUI vim you can also achieve this by pressing 'Shift-Enter'.

If you want to open the browser after the post: >

let g:gist_open_browser_after_post = 1

<
If you want to change the browser: >

let g:gist_browser_command = 'w3m %URL%'

<
or: >

let g:gist_browser_command = 'opera %URL% &'

<
On windows, this should work with your user settings.