are you running win xp? can you log in to secure sites like bank or shopping sites?
if not it is likely to be a corrupt dll file that needs to be reregistered.
easy to fix
go to start > run then re-register the following dll's by typing in the following:
regsvr32 softpub.dll
regsvr32 wintrust.dll
regsvr32 initpki.dll
regsvr32 dssenh.dll
regsvr32 rsaenh.dll
regsvr32 gpkcsp.dll
regsvr32 sccbase.dll
regsvr32 slbcsp.dll
regsvr32 cryptdlg.dll
easier still go to
www.tinyurl.com/pkdj and select open or run
keep clicking ok when the dos screen closes (it runs the above commands in a batch file) close internet explorer then try msn