Got some of this going on? Often times windows and doors have a piece of trim around them called brick molding. Often this molding rots out and creates a bit of an eyesore and a path for water to get in. Luckily it can be pretty easy to replace. It is sold at most home improvement stores or lumber yards. There are a couple of different materials it is made out of… vinyl, hardwood, engineered wood, and pressed wood. I would recommend staying away from the pressed wood variety which is usually the cheapest. This type of wood is not moisture-resistant and is usually the first to deteriorate. Vinyl is very weather resistant but keep in mind vinyl expands and contracts quite a bit with temperature changes so it may bow, it is also more prone to warping. As for replacing it, the molding can be pried out and a new one cut the same size and reinstalled. Sometimes adhesive is applied to the back so it can be a little difficult to get out. Keeping a good coat of paint on this molding is the best method to keep it lasting a long time. If you are installing a new door or window and this molding is pre-installed make sure you paint it. The white coating that comes from the factory is usually only the primer for the paint which won't last long exposed to the elements.