When someone asks me what antivirus they should use my typical response is “are you a safe surfer?”. If you are the type of person that rarely gets tricked into installing malware or unwanted programs then a free antivirus might work for you. What I really hate to see is people spending money on the Burger King and McDonalds of antivirus programs (McAfee and Norton). In my opinion neither of those programs are worth paying for, they appear to be much better at marketing than they are at protecting Windows PCs.
If you are going to spend money on an Antivirus then ESET NOD32 is the only one I have seen that actually protects people from drive by injections and the more common problem I see, repackaged programs. These repackaged downloads often include a number of unwanted programs like adware or “performance-enhancing” add-ons (also know as potentially unwanted programs or PUPs). These unwanted apps often slow down your computer and browser or might even cause your web browser to stop loading web pages. If you want real protection consider purchasing ESET NOD32 (you probably don’t need the more expensive Smart Security, just NOD32)
For a small business I recommend ESET file security and ESET endpoint security. You can get a 25% discount on ESET Small Office Security. Small Office Security includes protection for 1 file server and 5 computers.
Tips: Uninstall your old antivirus before installing a new antivirus. Reboot your computer after the uninstall even if it doesn’t prompt you to reboot. Install your new antivirus, check for updates, start your first scan. Let ESET NOD32 protect you from malicious software.
Notes: These are affiliate links but I use ESET on all of my personal/business computers. I would not recommend it if I didn’t use it. I have ESET running in a business environment on more than 100 computers and 5 servers, it works!