Hi, sounds to me like it could be a dying HDD. Try running a diagnostic program from the makers, IE if it is Maxtor then use Powermax from there website and burn to a disc, as it sounds like a bad HD. Do you hear any unusal noises from the HDD when activity occurs.
Also MSN won't be the problem, as the only reason you are not getting the error now, is cause probably MSn want to connect before it has fully loaded and this is causing the error in event log.
Also, if you look at event viewer and the chat log, the error and the resuming chat session, it is only 5 seconds between the 2, so unlike the machine shut down, restart, load back into windows, re-connect to the net and connects to MSN in 5 secs.
Check the HDD out and see what that brings back as maxtor drives can be problem-matic sometime. I just had to change a 6 month old 200 Gb Maxtor as it was clunking away and lagging.