HOW DO I FIX MY MSN?

EVERY TIME I TRY TO SIGN IT JUST COMES UP WITH WINDOWS LIVE MESSENGER HAS STOPPED WORKING, A PROBLEM HAS CAUSED THE PROGRAM TO STOP WORKING CORRECTLEY . WINDOWS WILL CLOSE THE PROGRAME AND NOTIFY YOU IF A SOLUTION IS AVAILIBLE.
BUT IT NEVER HAS AND WHEN I SIGN IN I CANT EVAN PUT MY ADI IN!!!!!!!!!!