Windows can become stuck a number of ways but the most common are expanding wood, paint or friction from moving parts. Especially when dealing with windows that may be subject to a lot of weather, such as them is not always easy. To fix a painted over joint or opening, cut the dried paint with a window zipper or a small knife. Slide the tool between the joined surfaces to "cut" the dried paint. From years of painting over existing paint, there could also be paint buildup that's making the window stick. In this case use a paint scraper and remove the excess paint. You can also remove the lower window stop and sand and scrap the parts that come in contact with the window. If this doesn't work or there is an excessive amount of paint buildup then remove the affected parts, sand, remove the paint and repaint. Reattach it to the window only when the paint is completely dry; if not, you'll end up with the same problem.

Sometimes there is too much friction between the sash channels. You can use candle wax or powder to lubricate it or make it slide more smoothly. There could also be weather stripping that is warped causing the friction. In this case use a block of wood and flatten the metal using a hammer.

Doors can become stuck for the same reasons as windows plus some added possibilities. The most common problem is the door getting stuck in the door jamb. To fix the problem, take out the hinges, unscrew the hinge from the door, and place a piece of cardboard behind it. If this doesn't fix the problem then the door may need to be modified. Determine how much of the door's edge needs to be removed by marking it with a pencil then use a sander and plane to remove excess wood.

Due to constant wear, the screw attaching the hinge to the door may become loose. In this case, remove the door and remove the hinges. Now use wood dowels and putty to fill in the old holes. Make sure the filler is as flush as possible with the door. Once the door is completely dry, sand the area and drill pilot holes for attaching the hinge.

Sometimes adjusting the stop is easier than fixing a warped or ill fitting door. To do so, pry off the stop, close the door and mark where the stop should be. Nail the stop in place and your problem should be fixed.

Sticking windows and doors will always be frustrating but with these tips you should be able to determine why and how to alleviate the problem.