OMG how can you go online without a anti virus DAMN, Google Avast and download the free version right now
I don't think it's that big of a deal. I've been a computer tech for 13 years now, and most computers I work on have Avast, AVG, Norton, or McAfee on them. It doesn't help as much as advertised.
I haven't had any of those on my home or work computers for years. I tell people to download Malwarebytes, and scan 1-2 times a week.
Personally, I have Malwarebytes and a heavily-patched hosts file, along with other programs I only use to fix computers with (ex. HijackThis).