Sometimes when I go on the internet a message pops up saying?

Question

Your certificate contains the same serial number as another certificate issued by the certificate authority. Please get a new certificate containing a unique serial number. WHAT SHOULD I DO

Answer 1

This may be phishing.

Where did you get your computer? If it was a privacy product, you need to buy a Windows and do the installation.

If your window is not a privacy product, then there may be some virus, you need to do a scanning.

Or someone has copied your window and using at the same time. You need to replace your window with a new one.