To repair a cracked window, start by preventing the crack from spreading by making a small arc around the crack with a glass cutter, and fill up small holes with transparent finger nail paint or shellac. Clean the cracked area with acetone and fill the crack with super glue.
Making a scored arc above and around the crack line prevents the crack from spreading. To seal the crack, fill it with a layer of super glue, wait for it to dry, and apply more light layers. Masking tape can also cover the crack. If the window has a shattered pane, keep cold air from entering the house by using double thickness garbage bags.