Here's a smaller version:
Quick tutorial:
Open up Paint - comes with most every installation in windows. Should be under Accessories in the Start Menu -> Programs -> Accessories path.
Once Paint is open, click on "File", then "Open" then browse to find the photo. Once you select the photo, the only thing you need to do is select "Image" and then "Stretch/Skew". When the new box pops up, there will be a section in it to choose the proportions of the image. It will default to 100 in both boxes(as in 100%). To make it half the size, put 50 in both of the boxes on the top(to keep it from distorting). Effectively you told Paint to scale the picture back 50%.
Play around with it for a little while to get the drift, after a while you can almost eyeball the pixels.