Firewall For Windows Machine On My Network

[Whitehill]

I have all Apple equipment on a network behind an Apple Extreme router in DHCP+NAT mode. We are reasonably prudent about which websites we visit and which email links to click. Now on the scene is a friend with a Dell laptop running some flavor of Windows. You can probably guess where I'm going now.

Yesterday she claimed her system had been invaded by some virus and nothing was working. Before coming to me, she called Microsoft support and paid $$$ for them to get rid of the problem. They warned her that the network she was on did not have a firewall.

Only after that, she came to me, all bent out of shape. For reasons I can't go into, I can't tell her to go find another network to use. Is there something simple and FREE I can do to provide more security to her? Isn't there some sort of firewall right on Windows she can configure until her fingers fall off?

 

[Satcomer]

it would help if listed the Windows Machine that had the virus/worm is a 7 and below problem.

My scare came to me at work when the encryption worm was going around last summer! My older work got the encryption worm! I caught it almost immediatly by first pulling the ethernet cable from the windows 7 work computer and then shut the Windows 7 machine down! After I found the manual way to get rid of the worm from the safe mode! Only some of his older pictures were encrypted but he didn't use them anymore anyway and all files on a networked drive now and our Windows 10 server was installed (pushed up in time)!

Now for a Firewall I would do a search for the best firewalls for a home! I'm only use to work firewalls!