While many newer double-hung windows are cordless, the older versions have sash cords that help sashes stay open, move up, and close properly. When these sash cords break, it does not mean you need to replace your windows. You can easily replace your sash cords as long as you have the right materials on hand.
To get started, you need a lubricant, such WD-40; a utility knife; a stiff putty knife; a hammer; a screwdriver; and new window cord roping. Once you have these materials ready, you can begin removing the broken sash cord and replacing it with a new one for better functioning double-hung windows. Get the illustrated instructions here by Dummies.