I just re-installed windows xp, and i noticed when you open the properties options on a file the extension is'nt shown like I would before, example " Drawing1.dwg", now all i see is "Drawing1", all I use to do was change the ".dwg" on properties, I use to be able to change the file to a for exmaple to a "tiff", now I cant, so what can I do, without chaning the application?