I downloaded msn messenger for mac when I got my mac about two months ago. It stopped working a few weeks ago (not sending/receiving messages) so I deleted it the other day out of my applications window, and tried to re-download a different version of it. When I do this, and try to log in, it tells me that the system cannot log me in. I don't understand if it is just the msn or if I need to completely remove the msn from my computer, and if that's the case, how do I do that? I'm new to mac computers, so please help me out!