If you have Firefox, you can right click > copy image, and then paste it into an image editor like Adobe Photoshop or Paint Shop Pro (even basic Microsoft Paint, which comes with Windows Start > Accessories > Paint, does the trick).

If that still doesn't work, you can push the "printscreen" button on the keyboard (on mine, it's next to "scroll lock" and "pause/break"), and then paste the entire image into an image editor. All you have to do then is crop to the image you want.