Though they aren't as common as they once were, you'll still see ads for Windows Registry cleaners around the web. These programs claim that they can speed up your computer by fixing issues in your registry, and ask for a payment in exchange for the service.

Don't believe this—registry cleaners don't make Windows any faster, and could even have the opposite effect by causing damage. Let's take a look at why.

What Is the Registry?

The Windows Registry is a large database that stores all kinds of information for both Windows and installed software. Every time you install or remove software or make changes to Windows settings, the registry is updated to reflect these.

You can edit the registry yourself using the Registry Editor tool. This is the only way to make a lot of advanced tweaks in Windows, since the settings they control aren't accessible anywhere else.

Windows Registry Example

See our introduction to the Windows Registry to learn more.

What Do Registry Cleaners Do?

When you see ads for registry cleaners or visit their websites, they'll make bold claims about their usefulness to your PC. One cleaner, for example, says that it will "clean, repair, and optimize your Windows registry to eliminate errors and crashes, and to restore smooth and stable operation."

They'll also tell you that "the registry can become littered with old entries", which will "cause error messages and slow the computer down." If you then proceed to install a registry cleaner, they'll scan your registry for "problems" and likely report hundreds of "critical issues" slowing your computer down.

Most of the time, these tools let you "fix" a few "problems" for free, then ask you to pay for a premium license to "fix" everything.

Clean PC Registry Scanner Scam

In reality, what registry cleaners claim are serious issues are not problems at all. It's true that uninstalling software can leave registry entries behind, or there could be unused file extensions that still have registry keys. However, these almost never cause Windows to slow down or throw error messages.

Even hundreds of orphaned entries won't amount to anything more than a tiny amount of data on your PC. Thus, cleaning the registry will not have any noticeable positive effect on performance. However, running a registry cleaner could actually cause damage to your system.

The Negative Effects of Running a Registry Cleaner

While running a registry cleaner is useless at best, it's dangerous at worst. As mentioned, the registry is home to lots of important values that both Windows and third-party programs use. If you delete, move, or damage these keys, critical system functions could fail to work.

Since registry cleaners are automated, there's a good chance that their registry scan could tag something as unnecessary when it's actually important. And unless you're a registry expert and check every entry before deleting them, you could cause major damage to your system by deleting something inadvertently.

windows registry cleaner ccleaner

Deleting important registry keys could cause some software to stop working, requiring you to reinstall it. Corrupting important keys might introduce error messages when you try to use certain Windows functions. In the worst cases, doing this might even screw up your system and require you to reinstall Windows.

There's no reason to risk these huge drawbacks just to remove a few hundred outdated registry entries—which will have no noticeable effect on performance anyway. Most of these fly-by-night registry cleaners are shady anyway, as they try to scare you with alerts and even bundle in more unwanted software.

What About Microsoft's Registry Cleaner?

Microsoft used to offer a registry cleaner called RegClean. This was back in the days of Windows 9x, when having too much in the registry could actually be an issue. Unsurprisingly, Microsoft doesn't offer RegClean anymore. It hasn't been supported since Windows 98, as it caused so many problems.

There's even an official Microsoft support page stating that the company does not support the use of registry cleaners. Consider how many utilities Microsoft has rolled into Windows over time: Windows 10 includes a built-in firewall, antivirus, file cleaner, disk defragmenter, and more. If Microsoft thought that registry cleaning was helpful, it would include a tool for this in Windows.

We should also mention CCleaner, which we once recommended as an OK option if you felt you really had to run a registry cleaner. Nowadays, you don't need CCleaner, and that includes its registry cleaner.

There Are No Registry Cleaner Performance Tests

Computer geeks love to squeeze every bit of possible performance out of their systems. There are all kinds of benchmark tests when a new CPU or graphics card launches, and people will tweak settings just to make a game run a little bit better.

There are no serious, legitimate performance tests showing that running registry cleaners improve performance. If they really worked, PC gaming enthusiasts would recommend running them for better game performance.

If you see registry cleaner performance tests, they are probably phony and either made up by the company or someone getting paid to sell one. The same goes for the "reviews" on registry cleaner sites.

Registry Cleaner Fake Reviews

How to Actually Speed Up Your Computer

Instead of running a registry cleaner, what can you do to actually speed up your PC if it feels slow? Thankfully, you have lots of options that bring a noticeable effect.

You should start by following our guide to cleaning up your computer. This will walk you through cleaning up large files, deleting old junk you don't need, and uninstalling bloatware. Doing all this will free up far more room than the scrap of space that running a registry cleaner reclaims.

Next, look into ways to make your computer run faster. These include steps that will actually have an effect, such as disabling unnecessary startup programs and turning off visual effects.

Startup tab in the task manager

You might even consider upgrading your PC's hardware for better performance, if you're able. Don't waste money on registry cleaners that do nothing—that money is much better spent on actual hardware boosts.

Don't Waste Time With Registry Cleaners

In the end, running a registry cleaner does not bring any perceptible benefit in performance. There's a good chance that a registry cleaner will break something on your system and cause far more problems than it could fix.

And even if they don't ruin something, using a registry cleaner is a waste of time (and perhaps money). Companies that sell registry cleaners try to deceive you into thinking these apps are a magic solution for PC performance problems. Don't buy the snake oil.