What about computer certificate errors?

Recently I on some websites, old can't open, prompt me certificate error, do not know how to go about, ask for help

The site certificate error, there are generally the following reasons: The first is the website certificate expiration, followed by the system browser itself set the problem, again is the computer may be poisoned, and finally there may be a website problem. The workaround is as follows:

First, the general website certificate has the date of promulgation and the deadline, if the certificate expires, we recommend that you download the certificate installation, to ensure that the validity of the certificate and the system time is consistent.

Second, the browser's security level is set too high can also lead to a Web page certificate error, the solution is to open IE browser, find the "Tools" menu in the top menu, find "Intel options" in the Tools menu, switch to the Security tab, and set the security level of the Internet to medium. It is also recommended that you clear the browser cache and clear the history.

Third, for poisoning, there are Trojans and other problems caused by plug-ins, it is best to update the virus after a thorough anti-virus, you can try to install the system.

Four, for the reason is the site itself, it is recommended to change the browser to try the first, if there is the problem of that is the site itself.