"Cleaning Windows - An Old Sticker Has Left a Sticky Mess"

Now here's a top tip for you....You know you can spend ages trying to scrape sticker residue off windows, even by using a razor blade doesn't always remove the sticky gum. Also any leftover adhesive collects dirt and sticks to it so it doesn't get any better. What to do in this case is firstly remove as much of the sticker and residue as you can and then spray a little penetrating lubricant like WD-40 onto the adhesive that remains. Then leave for a wee while and wipe off with a paper towel or rag and the remaining residue will come off completely.