If I could get a picture small enough to post I would. But for some reason I cant
Open in it microsoft Paint, which is in programs>accessories if you use the start button thingee on the bottom left of the screen.
Then, in Paint, press the resize button (should be in the toolbar just right of cut/copy/paste), then select "pixels" instead of percentage, then make sure 'maintain aspect ratio' is selected, then set horizontal value to something like 500-700, somewhere around that.
Then hit save as, and give it a different name so it doesn't overwrite the original. Then you rightclick on the icon of the photo you just saved and click properties and check what size it is. If it's a bit too big or a bit too small then go do it again but adjust a little.
That's how I do it anyway, it sounds annoying but actually takes about 30 seconds.