[Blackwater OPS]

Take a 2/4 block of wood and nail it to the door(center, slightly to the right(away from the hinges)), then take another and nail it(or 6 in wood screws or whatever, just make sure its not going anywhere) to the floor about 3 ft back (make sure the door can clear, but just barely) from the door the the inside. then insert a beam of wood in between the two. Presto, not pretty but 100% effective, any force exerted on the door will be transferred to the top of the door jam and the floor, unless they can push your building apart that doors not opening. As far as windows, you need bars, which can be installed in the inside, there are several brands that are which appear to be "window panes" and are not really detectable unless you are looking at them up close with the window open. If you are on the second floor or higher, leave it alone unless there is easy access to your window(WITHOUT a ladder). These simple things don't cost much and make it all but impossible for an intruder to get in your home, certainly not without you knowing it and having time to react. Also FYI a good shotgun can be had for <$150 and will be enough to stop even the most determined BG.