Just bought a new PC with Windows 8.1
It already has McAfee in it. I heard a few not so good things about it. I'm not good with computer. Is this a good security program or should I remove it and install something else? Can anyone recommend a good free antivirus program?
Thanks.

There are worse ones out there... and its far better than having none at all.

You WILL be needing to buy one however. What you likely have is a limited trial version good for only a short time. And yes you will have to uninstall it when you do. Different brand products tend to fight each other...not complement each other.
I recommend a security suite... not just an antivirus. There are threats beyond just viruses out there,

I'm with Smoothy. Macfee was a good product in the late 20th century, but it has gone down hill. I haven't used it in years so I can't say what it is like now though. I tend to shy away from it as it was a resource hog. My favourites right now are Norton and Kapersky.

It also depends on what you're doing online to what level of protection you need. If you're just surfing knitting sites then Avaria or Avast or AVG or one of the free scanners will do. AVG would be my free of choice. If you're doing more risky business online, porn, tumblr, pirating, p2p, torrents, etc. I would get something a little more robust and pay for protection. Most are reasonable at 50-100$/year. You just spent a lot on a computer, what is it worth to you? What happens if you lose everything?

I know a number of New PC come with this under a 1 year Sub , though yea it's not really a good Anti Virus program.

I find AVG is a better one than this one.

Anyway wait until the sub expires then if you want , get another Anti Virus program.

If you go the freeware route, you will need a couple of different programs. Avast's free version has a good scanner that goes all the way down to binary. Malwarebytes has a decent firewall. Ccleaner does a good job on junk files and clutter.

If you have the money, PC Pitstop has a decently priced suite with lifetime upgrades for one price and it covers up to 5 machines/phones.

What is your internet source/provider? Most cable companies provide free suite antivirus protection.

I always use this site to find the best peer-reviewed free software. Here is their page for AV:
Best Free Antivirus Software | Gizmo's Freeware

Comcast provides a free one. Why a new one with 8.1? 10 is standard and much better. You may be able to get 10 for free, check Microsoft website.