How to clean your Windows registry and speed up your PC

A cluttered registry can slow Windows to a crawl.

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Top 10 registry dos (and don’ts)

Messing with the registry—and doing so incorrectly—can destroy Windows and cause you great distress. Seriously. If something goes sideways in the registry you’ll be looking at a full reinstallation of your OS; that’s how dangerous it is to tinker with it. Here are the top 10 tips to keep your system running, and to keep yourself anxiety-free.


1. Back up your data. The best protection from registry hassles, or any computing disaster, is to have a current backup. As in, you ought to do one now while you’re thinking about it. See this article for some guidance.

Windows Restore

Always create a System Restore Point before you start mucking around with the registry. 

2. Back up your registry. Make sure to back up your registry before you open any registry cleaner. This is a bit redundant, since the registry cleaner will back up any changes it makes, but an extra level of security never hurts, and will help greatly if something goes awry. If you’re using an older version of Windows such as XP, you can use ERUNT (the Emergency Recovery Utility NT). If you’re on Windows 7/8/10 you can just create a System Restore Point to accomplish the same thing. 

3. Pay attention. In most programs that guide you with wizards it’s no big deal if you don’t pay attention and merely keep clicking the Next button. That isn’t the case with registry cleaners. Stay alert and read whatever the cleaning tool has to say, especially when it’s about to delete files. 

4. Minimize conflicts. When you begin scanning, make sure you don’t have any other applications running. It’s also smart to disable/unload any programs running in your system tray because open apps are constantly making registry changes, and you want the registry cleaner to do its work with no interference.

Taskbar Icons

Right-click any icons in your taskbar that are for programs running in the background and quit them before you begin.

5. Use caution. After the scan, the program will let you remove—or in some cases, repair—the registry errors. If you’re given the option, set the registry cleaner to remove errors only at the safest and least-intrusive level. (You can scan with more-aggressive settings later on.) Even using a cautious approach you might still see 1,000 or even 2,000 “safe” entries that need cleaning. For instance, Registry First Aid found 2,161 problems on the work system, of which about 1,900 were deemed safe to alter.

Whatever you do, never choose an “auto clean” option, such as the one in RegSeeker. Ever. They are not to be trusted.

6. Seriously, use caution. Choosing which of the errors to remove or repair can give you a migraine. We scan for things that look familiar. For example, we saw almost 100 registry entries left over from a package of Dell drivers that had been uninstalled months ago, and one registry cleaner spotted invalid paths to dozens of entries for MP3 files that were moved to a new location. Both of those catches were accurate, and gave us a sense that the program’s removal suggestions were accurate.

registry errors

Examine the errors you see and look for familiar programs before moving forward.

After a couple of days, if your PC doesn’t do anything weird, such as showing error messages on boot or when trying to launch a program, try another scan, this time allowing the registry cleaner to scan more aggressively.

Always examine entries marked with “Caution,” “Extreme Caution,” or some other indicator of risk very carefully. Unless you’re an advanced user and can clearly identify the scope of the entry, leave it alone. The reason is that, even if the cleaner offers an option to restore a deleted registry entry, restoring might not be possible if the DLL entry you just deleted is essential for your system to boot. Always be careful when making these decisions and error on the side of caution. 

Zooey at the beach josh norem

While it’s scanning, take your dog to the beach or go for a walk. Whatever you do, don’t use your computer for a bit.

7. Step away from the PC. Once you give the software the go-ahead and it starts removing registry entries, walk away from your PC. Play with the dog, have some coffee, or watch TV. This is for safety purposes: If you’re fiddling with the PC—moving the mouse, deleting desktop shortcuts, whatever—you’re making changes to the registry while a registry cleaner is working. Not a good idea.

8. Backup to the rescue. If you discover a problem (for instance, maybe Excel no longer launches), don’t panic. And don’t do anything aside from using the registry cleaner’s restore feature, which ensures that only the changes the program just made are reversed. That will usually fix the problem. If not, the next step is to restore the registry with ERUNTor via System Restore (see tip number 2). As a last resort, restore your PC with a backup program—which you certainly have, right? Right!??

9. Maintenance. You needn’t perform a registry scan more than once a month or so, especially if you don’t often make changes to your PC. Scanning more frequently won’t hurt anything, but you’re unlikely to see a significant performance boost if the program isn’t removing a lot of unneeded entries. 

10. Come one, come all. Are you a techno-fanatic who needs the registry to be squeaky clean, with absolutely no stray entries and trimmed of all fat? There’s no harm in using multiple freebie registry cleaners—provided you use them one at a time. If you are using a hard drive, you might also want to select a registry cleaner that includes a defragger (such as jv16 PowerTools or Registry First Aid), or choose a free defragger such as Auslogics registry Defrag.

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