Windoze 7 may not like the post box...............
I have a tip for what it's worth. When trying to remove broken bolts use some heat from a propane torch and then rub a candle on it. The heat will melt the wax and it will flow into the threads, making the bolts easier to remove.I used to try wd40 and similar products, but the heat would just burn them off, sometimes catching fire. The wax trick really does the job.