You can tell your browser what to do with files. Go to the browser's Preferences option, and when the Preferences window opens, click on the File Helpers button (that's what it's called in IE, forget what the equivalent is in Netscape or Mozilla or Omniweb). The hard part is finding the kind of file you're having the issue with, but once you do that, click on that option, click the change button, and adjust the bottom part of the window, particularly the "How to Handle" pop up menu.