Another recommendation for your security, take care with the fake AntiVirus, a fake AntiVirus is identificated by: the bad design, the repetition of “You need to upgrade to pay version”, and the suspicious detection of virus. Take care.
Nowadays few people fall into this (even the most lay). Beware of Chinese anti-virus (such as Baidu, 360 Total Security and Tencent), as they profit from advertising, and are not security-focused. In addition to collecting personal information that is useless to an antivirus.