Like disk defragmentation, registry cleaning has fallen by the wayside.

Back in the 90s and early 2000s, the Windows Registry used to be a performance bottleneck. Hard drives and CPUs were slow, the registry itself was poorly optimized, and that made systems slow to a crawl over time. Nowadays, hardware is so fast that it's negligible.

And yet many still swear by registry cleaners.

If your system is old, you may get a performance boost from cleaning up the registry. It may also be helpful if you have a slow HDD. Or it might just make your system feel faster by way of placebo. But even if it is just a placebo, maybe the perceived gains are worth it.

The bottom line? If you believe in the power of registry cleaners, stick to one of the ones below. Many contain malware, while others don't do anything. These, at least, have satisfied users.

1. Comodo PC TuneUp

Comodo PC TuneUp isn't a registry cleaner per se -- it's an all-in-one tune-up utility that happens to include a registry fixing feature. Note that registry fixing is distinct from registry cleaning, and that's why CPT is usually a safer way to go.

This tool only identifies and attempts to fix serious registry issues. It turns out that most registry problems, at least starting with Vista and beyond, are generally harmless. Instead of risking an accidental breakage in your system's registry, CPT only acts when necessary.

Not to mention that this tool is developed by Comodo, a company that specializes in cyber security and computer safety. They have a solid track record, and I find them more trustworthy than most.

2. JetClean

JetClean is a nifty little all-in-one tool that emphasizes a lightweight approach. It isn't bloated with unnecessary features like most PC optimization tools, and it's surprisingly effective considering it's been a few years since the app was updated.

In addition to cleaning the registry, JetClean has four other cleaning features built-in: Windows clean (operating system junk files), Apps clean (installed application junk files), Shortcuts clean (invalid shortcuts to files and Start Menu items), and RAM clean (for memory leaks).

Other helpful features include startup optimization, internet booster, performance booster, and the ability to create a portable version that you can carry around on a USB drive.

3. Wise Registry Cleaner

Wise Registry Cleaner is a 2-in-1 app that cleans the registry and tunes up system performance. It's extremely fast, thorough, and free to use.

In terms of how many registry issues it found, WRC only did worse than JetClean. I like the simplicity of the interface, and the inclusion of a registry defragmenter is a nice bonus. If raw PC performance is your main concern, the System Tuneup feature will help.

You have the option to upgrade to the Pro version for $20, plus $15 per year after that. The Pro version adds multi-user cleaning, automatic scheduled registry cleanings, and more advanced options for boosting system performance and backing up changes.

As far as I can tell, you can only download this tool off of CNET.

4. Auslogics Registry Cleaner

Auslogics Registry Cleaner is the only app on this list that strictly cleans the registry only. The fact that it only focuses on one task may be why it's so effective. And without other features to juggle, ARC is about as easy as it gets in terms of usability.

Before diving into ARC, be aware of two instances of bundleware in the installer. First, it'll ask if you want to set Yahoo as your browser homepage, and second, it'll ask if you want to install Auslogics Driver Updater as well. Uncheck both and you'll be fine.

ARC can back up your registry before applying changes, and restore the older version if anything goes wrong. It also has a feature for searching and deleting registry keys by hand (e.g. you're infected with a virus and the removal process involves a particular registry key).

5. CCleaner

CCleaner in last place? Blasphemy! While CCleaner may be the go-to registry cleaner for many, I've found that it tends to be too aggressive. More than once I've scrambled to "unclean" something that it wiped away, and sometimes it was irreversible.

It can be fine if you're careful, but we don't recommend CCleaner anymore due to malware and spying issues.

The free version of CCleaner is more than enough for casual users, but for $25 you can unlock CCleaner Pro. It introduces scheduled cleanings, real-time system monitoring, automatic updates (the free version demands that you update manually every time), and premium support.

Cleaning Windows Without a Registry Cleaner

If there's one reason to avoid registry cleaners, it's that they can cause unexpected system problems. Editing the registry is always risky, and tweaking the wrong key can be catastrophic. Always create backups first, but to be truly safe, avoid messing with the registry altogether.

Fortunately, there are ways to clean your PC without a registry cleaner. I highly recommend our guide to cleaning Windows 10 -- it covers a lot more than the registry and will have your system in tip-top shape.

How do you feel about registry cleaners? Which ones do you trust, if any? Are there any good ones we missed? Share with us down below!