Shoutbox

This problem is caused (as far as I know) by a software update corrupting the profile picture.

This is what you need to do:

Click on "Start > Run".  Type "regedit", and click on ok.
Then start navigating the tree structure on the left hand side to "HKEY_CURRENT_USER\Software\Microsoft\MSNMessenger\PerPassportSettings\{numeric string here}"
 
find the value thatstarts with "UTL"
Backup the {ID} key by go to File –> Export –> Then save the registry file.
 
After backing up, delete the UTL value, and restart your computer

MSN will now start but you will need to put up another display picture.