IIS authentication

Dear All,

I have website application hosted on IIS 6 ( windows server 2003 64 bit).

The application uses windows authentication.

for some reasons i had to change the logon name of one of the AD users from old logon name to a new one ( AD 2003)

Now when the modified user tries to login to the web application with the new logon name it fails and no logs recorded for this logon name in the windows or in the IIS I tried to restart the IIS and restarted the whole server but with no hope.

Kindly advice what should i do to let the IIS detect the new logon name ( it does not detect the old logon name as well).

Thanks