i get "Your connection is not secure" on all sites i go to including my Yahoo home page
Your connection is not secure
The owner of www.mozilla.org has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website.
Learn more…
Report errors like this to help Mozilla identify and block malicious sites
www.mozilla.org uses an invalid security certificate.
The certificate is not trusted because the issuer certificate is unknown. The server might not be sending the appropriate intermediate certificates. An additional root certificate may need to be imported.
Error code: SEC_ERROR_UNKNOWN_ISSUER
Alla svar (1)
There are several different possible reasons to get that error code. Could you review the possibilities in this article: How to troubleshoot security error codes on secure websites. Does that help point out the culprit?