This error is usually caused by the security parts in MSN Messenger not working correctly
Solution:
First, try the following: click start, then on run. Type: regsvr32 softpub.dll and press enter.
If MSN Messenger does not work yet after this, you can try closing Messenger then go to www.passport.net with Internet Explorer (also if you normally use another FireFox) then click on the sign in button, you may get a certificate dialog. Accept the certificate, now if you start MSN Messenger it should work.
If you did not get the certificate dialog and MSN Messenger still does not work, open the advanced settings dialog in Internet Explorer by clicking on the Tools - Internet options menu and then go to the advanced tab. Go down to the security section and make sure use SSL 2.0 and use SSL 3.0 are both checked.
