Unable to sign in

Yesterday I started having trouble signing in to MSN Messenger. Everyone
else in my family could still sign in OK but not me. After a couple of hours
of trying I set up a new MSN identity and began adding contacts. Now that
new account can't sign in but the rest of my family is still not having any
trouble. I just keep getting the message: "Sorry, we were unable to sign you
in to the MSN Messenger at this time. Please try again later." This is
followed by the troubleshooting option. Everything there gets a green
checkmark except wireless (I'm not using a wireless connection.)

Do you have any idea why only my Messenger isn't working when other people
are having no trouble on the same computer?

Thanks.