Gawd said:
Easiesy way as said is to hit the PRINT SCREEN button, which will take a picture of your monitor, basically a COPY function. Then open up PAINT or some other photo program and hit PASTE. This'll make an image of the entire window you just copied, then you'll have to crop it around the image you want, and SAVE AS making sure the extension is JPG. And that's it.
This is the easiest way to do it.
The problem is, you have no control over the resolution of an image.
Screen resolution is either 72 or 96 dpi, depending on software. Usually websites are 72 dpi but if you are working with Microsoft Powerpoint, the resolution is 96 dpi.
The best way to get images that are high resolution is to have a photo rendering software such as Adobe Photoshop. There are limitations to this as well. For instance, if you want a high resolution image, you must start with one first. Computers can't perform magic, just follow instructions. If you take a screen shot, it will only be good up to 96 dpi. You can, if you are a specialist in such things, render the image to be higher resolution through many tricks, but that's definitely not in the laymen's range of skills.
I can do such things and am willing to help you with the image if you want. PM if you want help.
Cheers.