Malicious software ('malware') has been around almost as long as personal computers and so having anti-virus software installed on your PC has been virtual necessity for many years. The dangers are much greater these days for PCs connected to the Internet, even though many Internet Service Providers routinely screen email for malicious attachments.
Anti-virus software is commonly provided with new PCs and so it's tempting to take the easy route and use whatever has been provided. However, it's much better to make this a considered decision and shop around. For example, there are well-respected anti-virus packages that are made available to private individuals at no charge - and that includes the updates that are needed to catch new viruses. And if you do get a paid-for package, you'll probably save money by shopping around for a replacement at renewal time rather than paying the renewal fee!
If you don't feel confident about choosing, installing or managing your anti-virus software, call me to arrange a consultation visit in which I will find out your needs and recommend the best option for you.