If your windshield wipers smear and streak, the problem may be nothing more than a film of oil and other foreign matter on your windshield. Wash the windshield with ammonia and window cleaner, using a clean soft cloth. Then wet it and turn on the wipers to see if they still streak.
If they do, check the blades; if the rubber is hard, brittle, chipped or cracked, replace the blades.
If the blades look okay, check the wiper arms to see if the spring inside the arm has weakened. Most service stations can test this tension in seconds, free. If the arm is weak, replace it with one the same length as the original or a universal arm, which can be adjusted. Pry the old arm off its splined shaft with a screwdriver, paying close attention to its position on the shaft and putting the new arm in the arm position.
To place wiper blades, see how the old blade is attached. Some have a button you can press to release the blade; slide the old blade out and the new one in. Other have a little spring device at the end of the blade. Press it together with your fingers and pull the blade out, then slide the new blade in. Still others are made as single unit with the device that holds them to the wiper arm. Remove by pressing a little spring at the end.
What if you turn on the wiper switch and nothing happens? In cold weather, the two most common causes are blades frozen to the windshield and frozen wiper linkage. Pull blades from the windshield by hand. If the linkage is frozen, chip the ice away by hand or, if you can get at it, run the engine and let the heat melt it.