What if the old doors and windows can't be closed?

If it is a steel door and window, it is because the foundation of the house sinks, which leads to the deformation of the door and window frame and cannot be closed. This needs professional decoration. You can apply for the maintenance of the property. If the wooden doors and windows can't be closed, they can be repaired by themselves: draw a line along the part that can't be closed with a pencil, then take it down, scrape off the marked part with a carpenter's plane and reinstall it. (There is no plane, you can cut it slowly with a kitchen knife, but pay attention to safety. )