Many people that I have helped with computer viruses had recently purchased new computers which have virus protection included in the software bundle. The problem with these virus protection programs is that the updates are only good for the first year. After that, you must pay a fee to continue to get virus updates.
Many consumers don't realize this and after the year is up, do not renew the membership with the anti-virus company, leaving their computer unprotected from incoming viruses.
So, if you purchased a computer over a year ago, be aware of this problem. You will need to pay the yearly fee to maintain your anti-virus updates or get another anti-virus software available on the market.
There are some anti virus programs that are free or low cost. I have found AVG to provide a good quality
free anti-virus program for home users. You can access the download at http://free.avg.com/us-en/download-avg-anti-virus-free
Also, remember to be aware of emails from senders that you are not familiar with. Also be very careful about opening attachments on any emails. Be sure you know who sent them to you. Even then, if your not sure, verify with the sender that they actually sent this attachment to you before opening it. Email attachments are one of the most common ways of spreading viruses.
So, be careful and happy surfing!