Internet Security
There are several companies that offer a Free Antivirus programme but this is essentially a small portion of their bought version and only covers a small amount of your security. This may be OK for someone that hardly uses the Internet but for most people this is inadequate.
The range of Internet Security programmes available is virtually unlimited. However you need to consider what is offered in the package, the ease of its installation and operation, and its general value for money.
Bullguard Internet Security is the suite that I recommend for the majority of home users, You can download a free one month trial version which is the full version without limits and allows you to see if it suits your needs.
Bullguard has less interference with your system than most other packages so doesn't slow it down like some do. It is easy to install and although you can adjust all sorts of things it works well in its default mode, ideal for most home users.
As a value for money, this package is unbeatable.