In the world of so-called PC cleaning, CCleaner is one of the most popular applications out there. It can delete temporary files, "clean" your registry, and can also clear files associated with your web browser like Microsoft Edge or Google Chrome. There's one downside though: it's a proprietary application that has suffered a pretty severe breach in the past, which is why many people eventually switched to the open-source and free BleachBit. However, you shouldn't use either application, especially if you're using a modern computer with a modern operating system like Windows 11.

Why you don't need registry cleaners anymore

Much of CCleaner is a leftover of a bygone era

PC "tuning" programs like CCleaner took off in the early days as they were capable of managing some things on your computer that Windows itself didn't. It could clean your temporary files, and remove registry entries that had been leftover from past applications that you had uninstalled. Nowadays, if you really care about uninstalling programs completely, you can use Revo Uninstaller to do that, but Windows will do just fine as well.

CCleaner used to be a program that was seemingly supported, as Microsoft even released its own registry cleaner called RegClean. It's no longer available, though, and Microsoft Defender now identifies CCleaner as a Potentially Unwanted Application. Furthermore, Microsoft even temporarily banned links to CCleaner from its forums in 2019. Microsoft's stance since 2018 on registry cleaners has also been abundantly clear.

Some products such as registry cleaning utilities suggest that the registry needs regular maintenance or cleaning. However, serious issues can occur when you modify the registry incorrectly using these types of utilities. These issues might require users to reinstall the operating system due to instability. Microsoft cannot guarantee that these problems can be solved without a reinstallation of the Operating System as the extent of the changes made by registry cleaning utilities varies from application to application.

Between everything, it's pretty clear that you probably shouldn't use a registry cleaner. The Windows cleanup tool is more than good enough, and the reason tools like Revo are okay is that they only remove the registry entries associated with the application currently being uninstalled. CCleaner, on the other hand, will try to identify registry entries that can be removed, which could lead to damaging your operating system.

In other words, CCleaner is a program that was purchased by Avast, has been marked as a PUA by Microsoft (for bundling software not made by Piriform), was the subject of a breach years ago that took months to disclose, and still offers tools that Microsoft says you shouldn't use. It's a pretty clear argument for why you shouldn't use CCleaner at this point.

BleachBit isn't a registry cleaner

It does regular cleaning

The reason people recommend BleachBit over CCleaner is primarily because of its open-source nature, but those who are aware of Microsoft's stance on registry cleaners recommend it because it isn't one, too. It can be fully automated via the command-line, It has a shredding option to remove files completely if you want to and supports a ton of different kinds of software for removing temporary files and stored data, and it can remove Windows temporary files, too.

The capacity for damage that BleachBit can cause is significantly reduced when compared to CCleaner, but to be honest, you still shouldn't use it anyway. Most applications can remove their own data through various settings menus, and Microsoft has since released a tool called PC Cleaner that will do all of the above but in a safe way. For finding larger files on your PC that you want to remove yourself, you should use something like WizTree to then remove them manually. You don't need a third-party PC cleaner anymore, and you can do more harm than good to your computer if you use one.

There are plenty of other ways to speed up your PC without a PC cleaner, and chances are that getting something like a new SSD if your PC doesn't have one will do significantly more for your PC's speed than a program like CCleaner or BleachBit would. These tools are just that, tools, but they're really not necessary these days.