have you done these:
1. If you haven't done so already, upgrade to the latest version of MSN Messenger:
http://messenger.msn.com/download
2. The date on your computer needs to be set properly -- double click the clock verify that
the time and date are set.
3. If you use a firewall (like ZoneAlarm, Norton Internet Security etc. ), it's possible
that Messenger doesn't have the correct rights to access the Internet, especially since you
upgraded. You may need to re/add Messenger to the allowed list of programs in your firewall
if this is the case.
4. If you disabled your firewall in the past, it still may be blocking Messenger -- try
restarting it and see if that helps the situation. You also might try uninstalling an
installed firewall, to verify that it isn't causing a problem (even if it is disabled).
5. Check your IE Security settings -- open Internet Explorer, click the Tools menu, then
Internet Options, then Advanced tab, scroll to the Security section, and verify that "Check
for server certificate revocation" is unchecked. Also verify that 'Use SSL 2.0' and Use SSL
3.0' is checked, then click OK.
6. Check for proxy setting in IE Connection settings -- open Internet Explorer, click the Tools menu, then choose Connections, then Advanced and check there are no proxy settings in place.
Internet Options,
7. Click Start, then Run, and enter the following:
regsvr32 softpub.dll
then click OK
and do the same for the following:
regsvr32 wintrust.dll
regsvr32 initpki.dll
regsvr32 MSXML3.dll