Unable to do actions requested in Livemail messages

Sometimes an email message that I received requires me to perform some action by way of reply and when I click to respond I get this message,

This file does not have a program associated with it for performing this action. Please install a program or if one is already installed, create an association in the Default Programs control panel. I have looked in the Default Programs control panel but don't know what to do. I would be much obliged for detailed instructions as to what I should do to fix this problem.