Web browsers are applications used primarily to display documents, files and media from the Internet, identified by a Uniform Resource Identifier (URI) that can be a page, image, video or other file. Some browsers require the use of add-ons or extensions to safely render the information they receive; others have systems built into them to perform the same functions.
TRUSTED BY
http://support.microsoft.com/kb/154359
registry changes are here
http://www.lockergnome.com/windows/2006/05/04/change-the-default-email-program-in-internet-explorer/