In this article, we answer every question you have about registries and registry cleaners. We also picked the top 11 best free registry cleaners for Windows 10 to help you get started. Read on for your comprehensive guide to using registry cleaner software.

Only 59% of U.S. households owned at least one computer in 2002. Twenty years later, computer ownership per household has reached 95%.

Most people know how to use a computer for necessary tasks. But not everyone is familiar with basic computer system maintenance.

There are thousands of apps and programs for improving PC performance. Some of these programs deliver on their promises, and some don't.

You may have heard of registry cleaners, but what are they exactly? Do you need a registry cleaner for your PC? What is the best free registry cleaner?

Registry cleaners are a great tool for improving and maintaining computer performance. However, you should be thoroughly familiar with registries and how they work before attempting to use a registry cleaner. Registry Cleaner Software FAQ Registry cleaners have many useful features and options. Before you dive into your registry and start cleaning up the junk, however, you have to know what registries are and why they're important to your PC.

What is a Windows Registry? The Windows registry is your PC's ecosystem. Windows consolidates system-wide information into a registry. Your computer constantly references these registry databases for crucial information, such as: • User profiles • Program locations • File types • Hardware configuration • Software settings Your computer also keeps track of your actions. It makes a new registry entry each time you add, remove, or modify important system components like programs and user settings. This creates an ever-expanding list of registry entries. In the very early versions of Windows OS, registry cleaning and error fixing were done manually. But as OS systems and computers evolved, registry cleaning became too time-consuming to go entry by entry.

What is Registry Cleaner Software? Registry cleaners, also called registry fixers or registry repair, were initially designed to clean up messy computer registries. A registry accumulates files and entries that no longer serve any purpose. In older operating systems, these junk files and entries would quickly bog down computer boot-up and performance. A registry cleaner could automatically scan entries and let you remove the junk. Registry cleaners could also repair or fix errors in the registry. Similar to defragging, registry cleaners were a regular function of system optimization. Common registry issues included: • Malware, spyware, and viruses • Blue screen of death • Duplicate keys • Improper system shut down • Invalid registry data • Missing or corrupted registries 

With newer technology, stand-alone registry cleaners aren't an obligatory part of routine computer maintenance like in the past. But they can still be useful to your computer system.

Why Use a Registry Cleaner? Most registry cleaner programs today aren't solely focused on registries. They come bundled as an overall package for keeping your computer clean, optimized, and safe. If you think of your PC as a car, registry cleaner bundles are similar to regular tune-ups and inspections. Although they won't fix major issues like a busted motor, they're good for preventive maintenance and keeping an eye on the overall health of your system. You may never have serious registry issues on your PC or laptop. It's still good practice to be familiar with the process, however. Similar to car maintenance, it also helps to know how to perform basic repair and cleaning tasks on your computer system. Your car battery might not die on you, but you still want to have the equipment and know-how ready to jump-start it in case it does. You also want to have a reliable registry fixer you're already familiar with using. And like a car engine, it also helps to know how a computer system functions so you don't unknowingly break it.

How Do Registries and Registry Cleaner Software Work? A computer registry is a hierarchical database with two main elements: • Keys: the container object • Values: the instructions Keys and values work similarly to folders and data in your PC hard drive. The keys sort all the values into a structure. The values contain all the data the computer needs to reference. A computer will contain millions of subkeys and values. A Windows registry cleaner scans all this data and reports back to you about what it finds. Not only does it save a massive amount of time, but registry cleaners are also integrated with other functions so you know: • The type of issue • How critical the affected files are to the system • How it affects other system functions

This can help prevent you from deleting or modifying critical files. Good quality registry cleaners come with auto-backup features so if you do make a mistake, you can restore the registry (and you should always back up your data on a regular basis anyway).

Does Cleaning the Registry Speed Up the Computer? The answer to this is situational and contextual. Using the car analogy, there's a big difference between maintaining a professional race car vs. a car that only drives a few miles per week. For a work computer constantly used by dozens of people a week, a free registry fixer can be super helpful for PC performance. For a laptop that's only used to catch up on social media and watch movies in bed during the evenings, you might not see much of a difference. Other factors that benefit more from registry cleaners include: • Older hardware • Low RAM • Outdated Microsoft OS versions • Work stations that continuously add, delete, and modify programs • Outdated or weak security settings

Additionally, if you have major PC performance issues, registry cleaning is most likely only one aspect. It's important to maintain the entire health of your computer system's interconnected functions. Registry cleaners can help speed up the computer if there are registry issues slowing it down. But it's only one part of the system, and not an automatic cure-all for every performance issue on your PC. This is why many registry cleaners come with other system functions, such as deleting temporary files, detecting malware and phishing scams, and clearing browser histories. The best registry fixers also boost your computer's speed through multiple performance-enhancing utilities, which include but aren't limited to only cleaning the registry. 

How Do I Manually Clean My Registry in Windows 10? It's not recommended to manually clean your Windows 10 registry. Unless you're a computer engineer, administrator, or someone with similar computer system education and experience, there's too much room for error. Microsoft understandably does not want casual users poking around a computer's registry. Incorrectly modifying the registry can break your system, and it can be very difficult to fix. Problems can include: • Degraded CPU performance • Slower startup and shutdown • Boot-up errors • Random system crashes • Dysfunctional programs and apps Even if you reinstall everything to fix a manually broken or corrupted registry, it's not guaranteed to fix the problem. And you could lose all your data. To maintain a registry, you need reliable third-party registry cleaner software to help you manage the process.

Does Windows 10 Need a Registry Cleaner? Registry bog isn't as immediately noticeable in newer OS versions, like Windows 10. And not every Microsoft app relies on the registry anymore. A Windows 10 registry cleaner is still useful to your computer's maintenance and performance, however, even with newer OS systems. Registry cleaners have many additional features and options besides registry maintenance. Depending on the features and options you choose, registry cleaners can help keep your data private, detect and remove malware, and optimize your registry along with other system functions.

How Do I Remove Malware From My Registry? Malware can be detectable through registry entries. Or the malware may latch onto the registry itself to take over your computer system. Keys commonly targeted by malware include: • Startup keys • Dynamic Link Libraries (DLLs) • Configuration settings • User profiles • Program launchers Malware is designed to go undetected by antivirus scanners. They can also be lightweight and work very fast. If you suspect malware has slipped past your antivirus net, registry cleaners with malware features can help you detect it. Some registry cleaners even come bundled with malware/spyware features so you can remove everything with one program.

Once the malware is removed from your computer system, it can still leave registry entries behind. To remove these malware traces, you can run a scan with your registry cleaner and let the program fix the entries. This saves you from wasted time and potential mistakes by attempting to remove them manually.

Be aware though, that some enterprising coders disguise their viruses and malware as registry cleaners themselves. It’s important to only install verified and safe registry cleaner software directly from the source.

Is There a Safe Registry Cleaner? No computer program is 100% foolproof. But there are legitimate registry cleaners you can use responsibly. Like any third-party program, you should verify the software is legitimate before installing it. This includes researching: • Company history • Licensing • Virus-free verifications • Data and privacy policies • Legal transparency • Regulatory compliance • Ease of cancellation and refunds • User reviews
 Some sneaky cybercriminals will also mimic legitimate companies. Once a free registry cleaner for Windows 10 is installed, you can double-check it using your anti-virus programs. The best safety is always knowledge. Knowing how to use a registry and how to tell a reputable company from scammers is the safest way to use a registry cleaner.

11 Best Free Registry Cleaners Registry cleaners are pretty standard in functionality. The best free registry cleaner for Windows 10 depends on you: what you need from a cleaner, how you use your computer, your system's specs, and other important factors. There are four main interconnected functions of registry cleaner software: • Performance • Optimization • Security • Privacy
 Some free registry cleaner options may include only one function, and some may include all four. You may need to access premium features if you download a solution that doesn't address your issues. If you need free registry repair for Windows 10, for example, a program like Razer Cortex won't be very helpful. But Restoro's tools are designed specifically for repairing Windows issues. 

1. CCleaner • CNET User Reviews: 4.5 out of 5 stars • Tech Radar Review: 3.5 out of 5 stars CCleaner is one of the most popular free registry cleaners. It's so popular that it was the target of hackers trying to capitalize on its wide usage, similar to other major tech companies. The software interface is relatively easy to use and is designed for both beginner and advanced capabilities. CCleaner is very upfront about what the cleaner itself can and can't do, and what programs you should integrate with it instead. Registry Cleaner Features • Supported versions: Windows 7 and up • Supported browsers: Chrome, Edge, Firefox CCleaner's free version comes bundled as a cleaner with standard privacy protections. This includes removing unwanted files and tracking data. Registry Cleaner Options The free version is completely free, without any underhanded fees or charges. The only downside is like a lot of freeware, it comes bundled with ads. The cost version adds a more robust system that includes managing: • Browser histories • Cookies • Temporary files • Driver updates • App updates You can try a free trial version that, unlike others, doesn't automatically charge you when the free trial ends. It simply switches you back to the free version instead.

2. Ashampoo WinOptimizer 2020 • CNET User Reviews: 4 out 5 stars • Tech Radar Review: 4 out 5 stars Ashampoo enthusiastically offers a wide range of freeware products, including registry cleaners. The Ashampoo WinOptimizer comes with a sleek, modern interface that's easy to use for beginners. Ashampoo is also transparent about what its free version can do for your PC. The WinOptimizer Free has step-by-step optimizer instructions and the complete instruction manual posted online, so you can check out their product and how it works before you even download it. Registry Cleaner Features • Supported versions: Windows 7 and up • Supported browsers: Chrome, Safari, Edge, Opera The Ashampoo WinOptimizer Free offers a lot for a freeware product. In addition to cleaning junk files, its features include: • Clearing browser caches • Deleting browsing history • System analytics • Permanently deleting sensitive data The free version also comes with two privacy functions: AntiSpy and Win10 Privacy Control. Registry Cleaner Options The free version is offered completely separately from the full version directly on their website. There's no attempt at tricking you into buying an unwanted or malicious product. The full version has an even more impressive bundle of features packed into its software, including a Privacy Manager, defragging tool, and Browser Extension Manager. You can also use a single license on a maximum of 10 personal computers.

3. IObit Advanced SystemCare • CNET User Reviews: 4 out of 5 stars • Tech Radar Review: 3.5 out of 5 stars IObit is a software company that focuses on system performance and security. In addition to registry cleaners, they offer anti-virus and anti-malware programs. The Advanced SystemCare interface is straightforward and customizable. The cleaner comes with an AI mode for smart systems management. Registry Cleaner Features • Supported versions: Windows XP, Vista, 7, and up • Supported browsers: Explorer, Firefox, Chrome Like CCleaner, the free version is much more limited compared to the paid program. However, the free version still packs a bundle of performance and security features. In addition to the registry, the cleaner can manage and remove files for popular apps, including: • Steam • OneDrive • Dropbox • Spotify • Adobe Lightroom The free version also includes assertive security options. It can wipe your data trail and patch security holes. It even blocks known hacking and phishing attempts. Registry Cleaner Options While the free version is powerful in its own right, you'll need the subscription version to take full advantage of all the security and speed-up performance features. Some features included in the free version are locked until you upgrade. The paid subscription options support either one or up to three PCs.

4. Iolo System Mechanic • CNET User Reviews: 3.5 out of 5 stars • Tech Radar Review: 4.5 out of 5 stars Iolo is another company that also focuses on security and performance software. Their programs are available in over 30 countries, with multiple language options. The System Mechanic interface focuses on simplicity. The dashboard is very clean, scaled-down, and minimalistic. It also offers in-product tutorials for beginners. Registry Cleaner Features • Supported versions: Windows 7 and up • Supported browsers: Explorer, Edge, Firefox, Chrome, Safari The free version of System Mechanic has an impressive list of features for freeware. These include RAM repair, removing junk files, and startup optimization. Iolo is blunt about how bad registry cleaners are actually counterproductive. Since enhancing system speed is a core part of their program goals, they even include a defragmenter in their free version. Registry Cleaner Options System Mechanic Free is already a comprehensive program that can do a lot for your system. The paid versions offer even more on the security side, including protection against credit card theft, malware, and password stealing. If you have a household that struggles with multiple PCs gaming and streaming simultaneously, you can also benefit from the enhanced speed-boosting utilities.

5. Restoro • CNET User Reviews: N/A • Tech Radar Review: 4 out of 5 stars Unlike other registry cleaner companies, Restoro also focuses on Windows repair in addition to speed and security. Although the company is relatively new on the scene, its products are already as advanced as other industry pros. Like Iolo, Restoro has a clean and modern interface. Restoro takes it a step further and streamlines its programs. The software is lightweight, easy to install, and doesn’t try to force any unnecessary extras into your system. Registry Cleaner Features • Supported versions: Windows XP, Vista, 7, and up • Supported browsers: N/A Restoro clearly outlines what it's capable of fixing and what will require additional programs. Unlike other registry cleaners, Restoro is exclusively dedicated to repairing Windows OS systems. It's the premier Windows 10 registry fixer. While it won't fix third-party programs, it can fix registry errors other standard registry cleaners can't touch, like the blue screen of death. And it can sometimes inadvertently fix programs that rely on Windows OS files. Registry Cleaner Options Restoro offers free deep scanning programs that can detect a wide range of issues, including malware. But the premium fixers are only available through the paid product. Other paid product features include: • Anti-virus • Windows OS recovery • Hardware analytics • App repair • OS file replacement If you have an older and/or slow PC, Restoro is definitely worth it. But you might not be able to fix everything with the free version alone.

6. Glarysoft Registry Repair / Utilities • CNET User Reviews: 4 out of 5 stars • Tech Radar Review: 4 out of 5 stars Many software companies that offer registry cleaners could be considered personal product solutions with business-use options. Glarysoft is more of a professional product solution with personal-use options. Even the interface uses a professional business design. And the streamlined dashboard only includes necessary utilities, much like Restoro. Registry Cleaner Features • Supported versions: Windows XP, Vista, 7, and up • Supported browsers: Explorer and Edge The Registry Repair is a free tool offered separately from Glary Utilities. You can use either the free Registry Repair or the free Utilities bundle. Registry Repair is only for scanning, analysis, and backup. Utilities Free offers over 20 tools, including: • Encryption • Registry and disk defrag • Anti-malware • Startup optimizer • Software updates • Privacy management Because Glarysoft is for more powerful business solutions, the free Utilities version is as comprehensive as other paid products. If you work from home, Glarysoft could be the best solution for you. Registry Cleaner Options It's hard to beat Glarysoft's free registry repair options for Windows 10. The free version takes care of almost everything you need for a home PC, unless you want to automate certain processes. The tech support is also limited with the free version.

7. Wise Registry Cleaner • CNET User Reviews: 4 out of 5 stars • Tech Radar Review: N/A Wisecleaner is a long-established software company that spans multiple countries and languages. They focus mainly on systems performance solutions. This program itself is easy to use. But the Wise Registry Cleaner interface assumes you already know what you're doing, and is more for intermediate and advanced users. If you're already familiar with registry management, this is the program for you. Registry Cleaner Features • Supported versions: Windows XP, Vista, 7, and up • Supported browsers: Internet Explorer, Edge, Chrome, Firefox, Opera, Safari Unlike other programs, Wise Registry Cleaner offers its automated process for free. And it includes customizable cleanup for advanced users. Other features include: • Auto backup • Settings restore • Defragging • Systems optimization Wisecleaner also allows you to include scanning exclusions. The cleaner will avoid files according to the keywords you set. Registry Cleaner Options The free program is pretty powerful, especially for home use. The Pro version includes a multi-user function for systems administrators. Wisecleaner also offers Wise Care 365, which includes cleaners and integrated security tools. Just like the cleaner, there's a free version and a pro version. The Pro-365 supports up to three PCs.

8. SlimCleaner • CNET User Reviews: 4.6 out of 5 stars • Tech Radar Review: 3 out of 5 stars Slimware is a system optimization-driven software company. Like CCleaner, the company has been the target of cybercriminals in the form of tech support scams. Comparable to Wisecleaner, Slimcleaner's modern interface is easy to use and operates at an intermediate level. And unlike other programs, Slimcleaner offers an interesting aspect: crowd-sourced solutions to issues. Registry Cleaner Features • Supported versions: Windows XP, Vista, 7, and up • Supported browsers: Edge, Chrome, Firefox The free version mostly includes scanning and junk removal features. The four main features are: • Disk scanning • Duplicate removal • Startup optimizer • Software manager Slimware lives up to its name: the program is very lightweight. It's only available for Windows, but can be used from a USB. So you can carry your registry cleaner from PC to PC if you have multiple devices registered. Registry Cleaner Options The premium version is basically an enhanced version of the free version. This means you won't get dozens of extra tools, but it also means the free version can perform most basic functions on its own. As another unique perk, Slimware offers a lifetime subscription. This subscription can be used on up to five PCs.

9. Auslogics Registry Cleaner • CNET User Reviews: 4 out of 5 stars • Tech Radar Review: (SpeedBoost) 4 out 5 stars Auslogics is an Australian software company that specializes in systems optimization and maintenance. Unlike other companies with similar products, Auslogics is actually Microsoft Silver Certified. Their Registry Cleaner has a modern, straightforward design that's well organized. The scanner is fast and light, without unneeded extra features clogging it up. Registry Cleaner Features • Supported versions: Windows 7 and up • Supported browsers: Edge, Firefox, Chrome Similar to Glarysoft, Auslogics provides stand-alone tools and bundles, with both free and premium versions. Registry Cleaner Free includes basic scanning and cleanup functions. Registry Defrag is a free tool to recompact the registry once it's clean. And Windows Slimmer Free removes junk files from across your system. There's also BoostSpeed 12 Free, which bundles these functions and more. Other functions include: • Removing temporary files • System optimization • Privacy tools • Speed boosts • App managers With so many free options, you've covered pretty much all the basics. The only downside is the minimal tech support with free products. Registry Cleaner Options Because the free programs are so comprehensive, the pro versions are just enhancements of the basics. The premium products also offer process automation and regular tech support.

10. Razer Cortex • CNET User Reviews: 4 out of 5 stars • Tech Radar Review: 3.5 out of 5 stars Razer is a gaming-focused company that's been around since the late '90s. Like Slimware, they offer software solutions with more unique features. The interface is gamer aesthetic-based, so you won't have to sacrifice style for functionality. It's divided between game optimizers and system optimizers.  Registry Cleaner Features • Supported versions: Windows 7 and up • Supported platforms: PC, Console, Mobile Razer Cortex isn't a traditional registry cleaner but uses many of the same tools and functions to boost gaming and systems performance. These features include: • Junk file removal • Defragging • App managers • Cache cleaning Razer Cortex has an added feature: actively managing background processes. You can shut down certain processes to speed up the CPU and free up memory while gaming. After you're done, the program automatically turns them back on. Registry Cleaner Options Registry Cortex is free across the board. There are no premium or pro features to pay for, and it even includes a price comparison tool for game price shopping. You can still purchase Razer gear in the store, however, if you want to support the company.

11. BleachBit • CNET User Reviews: 4 out of 5 stars