DefaultBrowser allows you set the default web browser for your user profile in Windows XP, without affecting the other users. Note that the user interface in Windows XP does not provide an option for setting the default browser for each user. The browsers you see in the Preset Configuration are tested and working flawlessly as user defaults.
Apart from the Presets list, there is an option at the bottom which allows you choose the Web Browser program file and set it as the default. You may use this section if your favorite browser is not listed with-in the Presets. As you read in the dialog, this method does not work with all the browsers. Some browsers pass command-line arguments for the respective file associations and some use their own type libraries. If the results are not satisfactory using this method, you can undo the configuration by clicking the "Clear Per-User setting....." button.