If the above does not work try a ping command to test
Go to search type cmd, in cmd type yahoo.com
in the black window that appears, type in
ping yahoo.com /t
LOL or is it msn.com now. I dont really use these things and may not be up to date.
and press enter. (press ctrl + c to stop the test)
If the requests did not time out your internet conncection is good.
If you get some success and some failure you have a bad connection.
if you get 100% replies, you have a firewall or virus blocking your connection. if you get timeouts only, you're not connected.
lastly, pay attention to the time, anything over 500ms means you have a poor internet connection, dial up answers pings in about 100ms.
If the results turn out poorly. Take a general ping test to see if it is all your connections or only msn or yahoo (try both)
http://www.pingtest.net/