After much searching and trying just about everything i finally fixed the MSN Messenger Error 80072745 login issue by doing the following: On the netgear router there is a setting to enable IM .... even though i had this set to enable i believe the router data file may have been corrupted. I enabled the following services inbound..... 443, 7001, 9 and 1683 and saved the settings. Then i applied the IM enable setting again. This then allowed me to login to MSN. i then removed the ports in services which disconnected me from MSN then reapplied the IM setting again.... bingo it all works..... I am not sure but i feel there may be a configuration save issue with the netgear router or the configuration can become corrupted for whatever reason.