If you have IE 5, go to Tools->Internet Options and click the Program tab. At the bottom of the selection boxes there's a little checkbox that says something like "IE should check whether it's the default browser." Then quit IE and start it up again. I think it should ask you if you want to make it the default, blah blah. There should be a similar function like that for Nutscrape, but I don't remember how to take care of that (should be in the "Help" section - maybe do a search for "default browser"😉. Hope it works...