0x80070057 error code

When attempting to sign into MSN Messenger 6.2 my client
receives a cannot connect message and a 0x80070057 error
code. I am able to log him into Hotmail and .Net with the
same sigin and password combination that does not work in
MSN Messenger. He is using Windows XP Pro SP2.

I have removed the Norton Firewall and checked on all of
the points that Jonathan Kay generally posts as an initial
response. Nothing works. The problem appears to have
started when he was unable to remember his sigin and
password and entered anything and everything out of
frustration. Any help resolving this is appreciated.