Take the picture with the "Print Screen" and "Function" buttons on your keyboard. Open a photo editing program like Photoshop or Paintshop Pro or even MS Paint, paste the picture there. Crop or resize to whatever you want, save it. (JPG or GIF format are clearer but Paint doesn't give you that option.)

Go online to a host site like Photobucket.com and set up a free account. Upload the pic. Highlite and use the IMG tage they give you in your post. There is your pic.