MSN Messenger won't connect
From WikiTechia
An infuriating problem at times can be if MSN Messenger won't connect even though you are sure you didn't change your saved password and your internet connection is working fine (and assumingly MSNs servers are fine as well).
Solution
System Time
There is a possibility that your system time and date is not current for whatever reason. Make sure your time and date are correct.
The reason authentication does not work is because it is done over a secure connection. A secure connection is established with certificates that are only valid for a certain amount of time and if your time is incorrect, then the certificate will be rejected.

