This could be corruption in accounts so you can try creating new accounts and see if this resolves the problem. Another thing to consider is that MSN have now got a higher security feature that will not allow you to login for a certain time if you get the password wrong the first time. Other than that, you could try reinstalling MSN. All fails, then try recovery but you will lose all personal data.
Alternatively, if you bought PC Performance, then you can ring PC ServiceCall on 0870 850 0653 and they will talk you through it, but you must have warranty else they will tell you to ring the premium rate s/w line.
Another thing i can suggest is to try http://webmessenger.msn.com/ and see if any problems here.
Kash, PC ServiceCall, April 2006