Error Code 166-169-021 is a malicious domain name involved in showing the wide range of intrusive alerts saying that your computer is horribly infected. There is a reason why your browser spews out such a number of annoying pop-ups. Your PC is most likely indeed infected by adware, however, such Error Code 166-169-021 pop-ups are simply the part of that adware. So, in this guide you will find out helpful information to get rid of Error Code 166-169-021 pop-ups and other related malware from your system.