Sarah accidentally spilled wine in her computer, so she's ordered a new one. She's borrowing a computer from a friend in the interim. She has a variety of email accounts though, and she wants to access those, but she doesn't want to leave her account information saved on that computer. Sarah should create her own account on that PC. Then, before she gives back the computer, she can just delete that account. Sarah can just go into Users section of Control Panel and make a new account with administrative privileges. Then log out of her friend's account, and log into that account. That way, anything she does on the computer won't be left around to get mixed up with her friend's data.
Sarah is also wondering what the best antivirus is. Leo suggests not using antivirus. Leo says there are a number of big name antivirus programs that have left holes on systems that have been compromised. Windows 10 actually comes with a built-in antivirus and malware removal tool, and that's enough. The problem with installing an antivirus is that it gives you a false sense of confidence. In the best case, it will find about half of the things that can attack you. The second problem is because these programs operate at a low system level, if they have any flaws, they're opening the system up to bad guys. If McAfee is already on the system, Leo suggests uninstalling it.