You say you can't see your file extensions after you create a zip file or other file. The extension is there. My guess is that you have your file extension switch turned off. In XP I believe you will find it in your setup section that is where you turn on/off your display, hidden files, etc. You either see all file extensions or none. "Adding" .xxx to a file name doesn't make it ABC.xxx it makes it ABC.xxx.hiddenextension.