Comcast provided Norton Security Suite free to their customers, but that’s ending today. I have my own router/modem and don’t want to lease their Xfi Gateway? Which has its own security, so it looks like I’m on my own. 
Norton is offering a special deal to Comcast customers on their 360 deluxe at $15 for the first year, but then it jumps to over $100 per year.
I don’t even know what all that means! I’ve been reading up on it and am getting a headache.
Any suggestions to protect a HP PC from virus and malware threats?

Norton is offering a special deal to Comcast customers on their 360 deluxe at $15 for the first year, but then it jumps to over $100 per year.
I don’t even know what all that means! I’ve been reading up on it and am getting a headache.
Any suggestions to protect a HP PC from virus and malware threats?