jendor, hi, I congratulate you for looking after your kids even when they are on the internet, especially by using IM chat apps such as that from MSN. As a parent, your concern is certainly warranted and you have the right to know what your kids are doing online, even if they do not want to give you access to whatever they are doing online. In your case of how to get access to your son's MSN IM account and check on chat logs and such, you do in fact need your son's password in order to access his MSN IM account. However, this does not mean there is no other way to access your son's IM account just because you do not have his password.
Now, there are, in fact, as well other ways to go around the password access problem . Most people do not know there are indeed some very good programs both sold to the public and otherwise not, that you can installed on your son's PC and GAIN access to his chat logs and more. These are tools of the trade private investigators use to secretly spy on others on behalf of their clients to easily GET passwords by way of recording keystrokes, GETTING copies of his e-mail (both sent and received) messages directly sent to your own e-mail account in real time in a matter of minutes and everything else you would like to know about what your son may be doing or involved in.
HERE ARE some sites of these excellent stealth monitoring and info-gathering tools that I have used for years and highly recommend:
(1) eBLASTER 3.0 at
http://www.spectorsoft.com/products/...asp?refer=5988
TeBlaster 3.0 is the best stealth monitoring software you can buy. It is a little pricey at $99.00 US but well worth the investment.
(2) Password Recovery Toolbox
http://www.rixler.com/password_recovery_toolbox.htm
Or, if you prefer other really good eBLASTER alternative softwares at a lower price, may I also suggests
(3) PC Agent or Mini Key Log which you can get at
http://www.blue-series.de/home/home_uk.htm
PC AGENT sells for 39,95 EUR or about $48US.
Mini Key Log sells for 24,95 EUR or about $30US :D