From your first message, Leslie, I'm making a guess that the update your received for Windows had something to do with the certificate store. Web sites use certificates to prove who that they are who they claim to be and that the connection is secure. The operating system (i.e. Windows) has a list of trusted certificate authorities, so when a website identifies itself using a certificate signed by a given authority, Windows will check it against its list and see if it recognises it. If it does, all well and good; if it doesn't you can get a number of different error messages.
