1. Open Internet Explorer.
2. Click on 'Tools' then scroll down and click on 'Internet Options.'

3. Click 'Content' tab. Click on icon labeled 'Certificates' under the 'Certificates' heading (this is the second heading on this tab).
4. Click on the small right arrow on the right side of this window until you see 'Untrusted Publishers.' Then click on the certificate that is causing a error message.
5. Next, click 'Remove' to delete that certificate.
6. Click 'Close' and then 'OK' once you are done deleting problem security certificates.
7. Exit Internet Explorer to reset the browser.