MS Internet Explorer error......Browser Not Supported

hello every1

                 Well i have windows xp in my system and also MS Internet Explorer verion 6.0 ... the problem started 3-4 days ago when my explorer started to show error " Browser Not Supported......Microsoft® .NET Passport no longer supports the Web browser version you are using. Please upgrade to a current Web browser, such as Microsoft Internet Explorer version 4.0 or later, or Netscape Navigator version 4.08 or later."

whenever i open hotmail.com it shows the smae messgae and also when i compose a message a in yahoo mail.i can't see the " Color and Graphics " bar.......

can any1 help me..... i will be very much thankful

                                                                      regards
                                                                                  Ahsan.......