How to Install CCleaner and Optimize Your PC in 5 Minutes

Your PC feels slower than it used to, your storage is nearly full, and you do not want to spend an afternoon fixing it. A cleanup tool can handle the easy wins in a few minutes.

CCleaner is one of the best-known options. This guide shows you how to install CCleaner, avoid the common installation traps, and run a quick optimization pass. It also covers the parts most tutorials skip: the tool’s security history and the settings you should leave alone.

What you need: A Windows PC, an internet connection and about five minutes.

Before You Start: Download From the Right Place

Search results for CCleaner are crowded with low-quality pages. Some are “help center” pages that push you to call a phone number for installation support. The software is free to download and install, and you never need to phone anyone to do it.

Follow these rules:

• Download only from the official CCleaner website at ccleaner.com/ccleaner/download.
• Ignore any page that asks you to call a number or pay for installation help.
• Never download a “cracked” or “full version” file. These are a common way to spread malware.

Step 1: Install CCleaner (about 1 minute)

1. Open the official download page and choose the free version.
2. Run the downloaded installer file. If Windows asks for permission to make changes, click Yes.
3. On the first setup screen, click Customize instead of accepting the default install.
4. Uncheck any extra software offers, such as another browser or an antivirus program.
5. Click Install, then wait for the setup to finish.

The Customize step matters. Over the years, free CCleaner installers have offered bundled software, including Google Chrome and Avast or AVG antivirus products. Microsoft’s security team has said that these bundled apps are legitimate, but that some users install them by accident, and Microsoft Defender has flagged certain CCleaner installers as a potentially unwanted application for that reason. The exact offers can change between versions, so read each checkbox before you continue.

Step 2: Run the Main Cleanup (about 2 minutes)

1. Open CCleaner and go to the cleaning section (often called Custom Clean).
2. Close your browsers first. CCleaner cannot clear files that are in use.
3. Click Analyze to see what can be removed and how much space it would free up.
4. Look through the list. If you are not ready to sign out of websites, uncheck browser cookies.
5. Click Run Cleaner to remove the selected files.

This step clears temporary files, browser caches, and similar leftovers. The space you recover depends on how long it has been since your last cleanup. Do not expect a dramatic speed boost from this alone, because deleting cache files mainly frees disk space.

Tip: Browser caches exist to make websites load faster. After a cleanup, your first visits to your usual sites may feel slightly slower while the cache rebuilds.

Step 3: Trim Your Startup Programs (about 1 minute)

Programs that launch with Windows are one of the most common causes of slow boot times. This is where you will often see the biggest improvement.

1. In CCleaner, open the Tools section and choose Startup.
2. Review the list of programs that start with Windows.
3. Disable (do not delete) anything you do not need right away, such as chat apps, game launchers or updaters you can open manually.
4. Leave your antivirus, drivers and anything you do not recognize alone until you have looked it up.

Disabling a startup item is reversible, so you can switch it back on if something stops working. Windows also lets you do the same thing in Task Manager under the Startup apps tab, so this does not require CCleaner.

Step 4: Remove Software You No Longer Use (about 1 minute)

1. Go to Tools and choose Uninstall.
2. Sort the list by size or install date.
3. Select programs you have not used in months and click Uninstall.

Removing unused apps frees storage and cuts down on background processes. If you are not sure what a program does, search for its name first.

What to Skip: The Registry Cleaner

CCleaner includes a registry cleaning tool, and many guides tell you to run it. You can safely skip it.

The Windows registry stores configuration settings. Microsoft has long advised caution with registry cleaners, stating that mistakes in the registry can cause serious problems, in some cases requiring a Windows reinstall. The performance benefit of removing a handful of broken entries is small, and the risk is not worth it for most people.

If you choose to use it anyway, let CCleaner save a backup of the registry when it asks, and create a Windows restore point first.

Is CCleaner Safe?

CCleaner’s reputation took a serious hit in 2017. Attackers compromised the software’s distribution, and version 5.33 contained a malicious payload. Security researchers at Cisco Talos reported the problem, and the compromised version was available between August 15 and September 12, 2017. Avast, which had acquired CCleaner’s developer Piriform only weeks earlier, estimated that about 2.27 million users had the affected version.

That incident is years old, and the company fixed the issue and released clean versions. Still, it is a good reminder of three habits:

• Download only from the official site.
• Keep the software updated. Check CCleaner’s update settings to see whether automatic updates are on. If they are off, look for new versions yourself from time to time.
• Do not assume that any cleaning tool is essential. Windows has built-in options too.

Free vs. Paid: What You Actually Need

The free version covers the manual cleanup steps in this guide. Paid plans add features such as scheduled cleaning, automatic updates and a driver updater. According to one third-party pricing tracker checked in March 2026, the Professional plan was listed at $29.95 per year and Professional Plus at $44.95 per year. Prices change, so confirm them on the official site before you buy.

For most healthy Windows 11 PCs, the free edition is enough if you only want an occasional cleanup.

Built-In and Alternative Options

You do not have to use CCleaner at all. Consider these alternatives:

How Often Should You Run It?

Once a month is plenty for most people. Running a cleaner every day has no real benefit, and it can slow your browsing by clearing caches that you will need again right away.

FAQ

How long does it take to install CCleaner?

The download and install take about a minute on a typical connection. A first scan and cleanup add a couple more minutes.

Is CCleaner free?

Yes, there is a free version with manual cleaning, startup management and an uninstaller. Automation and some advanced features require a paid plan.

Will CCleaner make my PC faster?

It can help in two ways: freeing disk space and reducing the number of programs that start with Windows. It will not fix an aging processor or too little memory.

Should I use the CCleaner registry cleaner?

Most people can skip it. Microsoft cautions against registry cleaners, and the benefits are minor. If you use it, back up the registry first.

Why does Windows Defender flag CCleaner?

Microsoft Defender has flagged some CCleaner installers as potentially unwanted applications because of bundled offers in the free installer. Choose Customize during setup and decline anything you do not want.

Can I uninstall CCleaner later?

Yes. Open Windows Settings, go to Apps, select CCleaner and click Uninstall.

Conclusion

Installing CCleaner takes about a minute, and a basic cleanup takes only a few more. The main steps are to download it from the official site, click Customize to decline bundled extras, run Analyze and Run Cleaner with your browsers closed, and disable startup programs you do not need. Skip the registry cleaner, and keep the software updated.

Set a monthly reminder to repeat the routine, and your PC will stay tidier without much effort.

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Sources and Further Reading

• Official CCleaner download page
• Cisco: Consumer Security Alert on the 2017 CCleaner breach
• The Register: report on the tainted CCleaner downloads
• TechXplore: Microsoft’s potentially unwanted application flag for CCleaner
• OnMSFT: Microsoft’s note on bundled CCleaner offers and registry cleaners