Mike bought a new Dell Laptop with Windows 10 and now his printer isn't supported. Leo says that a lot of people are discovering that many printers and other peripherals don't work with Windows 10. But that isn't the fault of Microsoft, it's the manufacturer of the printer. They haven't made a driver for it. And they most likely want to sell him a compatible printer instead. There are other choices, however. CUPS drivers are generic and could work. They're based on Linux and he would just need a CUPS to Windows driver to serve as a middle man. Fortunately, printers are cheap if he does need to get a new one.
Mike is also wondering whether or not to buy antivirus for Windows 10. Leo says he doesn't recommend antivirus programs anymore. Viruses spread faster than an antivirus company can get out definitions for them. They can guard against old stuff, but they usually miss new viruses and provide a false sense of security. Leo says that Windows also has it's own antivirus built in now. So Mike won't really need one. His online behavior is more important.