How to set notepad, or any other program, as the default browser?

How to set notepad, or any other program, as the default browser?

I am interested in setting a standard executable file, such as notepad.exe, as the default Web Browser in Windows XP, SP3. By being the default browser, I mean that the icon of the executable file is listed at the top of the start menu and is associated with .html, .htm, etc files.