How to delete duplicate files to save computer memory using CCleaner

Running out of storage space used to mean spending a weekend digging through folders, but now there's a better solution. CCleaner scans for duplicate files in just a few minutes, then lets you decide which ones are safe to delete.

Annoying problem that slows down your computer

Your Windows laptop may have been running out of space for weeks. Every time you try to install a new file or copy a large folder, the storage bar in File Explorer turns red. At first, you might think the usual suspects are to blame: large videos, multiple downloads, and maybe too many apps. But on closer inspection, the problem turns out to be much simpler.

Duplicate files can accumulate over years without you even realizing it. They don't directly slow down Windows, they just take up space. And once your storage space gets too low, your entire system slows to a crawl.

Old backups, copied photos, and multiple versions of the same installer are all over the place, no matter how many Windows backup tips you follow over time. Cleaning them up manually takes days, so many people end up turning to CCleaner, a tool they’ve heard of but never used.

How to Free Up Gigabytes of Space with One Simple Tool

Many people think of CCleaner as a tool for deleting temporary files and junk files, so they are surprised to see that it also has a built-in Duplicate Finder feature. Located in the Tools menu , this feature allows you to scan any drive or folder for identical files with just a few clicks.

When you start your search, CCleaner lets you choose how to compare files: Name , Size , Modified Date , or Content . While the first three options are faster, they can sometimes be misleading, as files with the same name or size are not always exact duplicates.

However, the Content option performs a deeper analysis by examining the actual file data. For the most accurate results, you should only select Content and deselect the other options.

With those settings, scan both the C: and D: drives. This completes quickly on the example setup, sorting the results into groups that show exactly where the duplicate files are stored. This makes it easy to keep one copy and delete the rest.

Before deleting, CCleaner clearly warned that the files would be deleted permanently and asked for confirmation. Much of the space on the drive was taken up by duplicate photo folders that had been copied multiple times; project files were stored on both the laptop and the backup drive.

After going through the list, you can delete any duplicate files you don’t need. When you’re done, you’ve reclaimed nearly 7GB of storage. That’s a huge relief, and for the first time in a while, browsing through folders isn’t a pain.

Why do people trust this app and what surprises them?

Before installing CCleaner, many people were concerned about whether it was trustworthy. Its history has not always been transparent. In 2017, a backdoor was installed in a version before it was released to users, with 2.27 million people downloading the compromised installer. This came just weeks after Piriform, the developer of CCleaner, was acquired by Avast. To their credit, Avast has released detailed reports explaining the issue and how it will secure future updates.

The troubles don’t stop there. In 2018, CCleaner was criticized for adding telemetry data and forcing users to auto-update, which many users had trouble disabling. By 2020, Microsoft had flagged a number of installers as Potentially Unwanted Applications (PUAs) because they included additional incentives. None of this malware was outright malicious, but it did hurt the tool’s reputation.

So why would anyone give it another chance? First, Avast has been transparent about the 2017 breach and fixes. Second, they only download from the official website and stick to the free version, avoiding extra features. And third, they only use the Duplicate Finder feature, which simply identifies duplicate files. Skip the more dangerous tools like registry cleaners.

With those precautions in place, you should feel confident enough to incorporate CCleaner into your workflow. Hopefully, by now, it will be a reliable tool rather than a risk.