Bart uses Piriform CCleaner. Leo says that there's a new warning out to avoid CCleaner. Leo says that Microsoft Defender is flagging CCleaner has unwanted software because it includes other apps as part of the download. None of which Leo recommends. It's always best to avoid software that comes with a separate installer that ads other apps you don't want. CCleaner has addressed that issue to make sure it's no longer flagged.
Janet is worried that she needs to clean up her system and have a separate antivirus system. Leo says no. You don't. You don't need a third party cleaner and you don't need a separate AVS app. Windows Defender is just fine and it comes with Windows 10 for free. But even the best AVS isn't going to protect you against your own online behavior.
Mark uses a registry cleaner and wants to know what Leo thinks of using them. Leo says that a well designed OS shouldn't need one for maintenance, and a registry cleaner can create more problems than it can cure. He thinks that the promise of fixing the registry to improve performance is simply snake oil, and comes from the older days when Windows just wasn't that great at managing it's resources.
Rick wants to clean up his PC and make it run faster. Is there a piece of software that can do that? Leo says no. That's snake oil. He can run CCleaner and a registry cleaner, but that's risky as cleaning the registry can cause the OS to stop working. He can also optimize the disk, but that isn't necessary anymore since hard drives are very efficient these days.
Hamit keeps seeing commercials about speeding up computers using a registry cleaner and a service. Leo says that first, he doesn't need to pay someone to speed up his computer. He can easily do it himself. The best way to speed it up is to back up his data, format the hard drive and then reinstall and update Windows. He can use a registry cleaner, but often they are way too aggressive and will mess up Windows drastically. So he should just make a point to do spring cleaning once a year, and he'll keep his computer in good shape.