CCleaner FAQ
Find answers to common questions about CCleaner, from installation to advanced features.
General Questions
Q: What is CCleaner?
A: CCleaner is a system optimization and privacy tool for Windows, Mac, and Android. It removes junk files, cleans browsing data, fixes registry errors, and helps speed up your computer.
Q: Is CCleaner really free?
A: Yes! CCleaner Free is completely free forever with no trial period, time limits, or required payment. The free version includes disk cleaning, registry cleaning, and basic tools. The Pro version ($24.95/year) adds automatic updates, real-time monitoring, and premium support.
Q: Who makes CCleaner?
A: CCleaner is developed by Piriform, which was acquired by Avast (now part of Gen Digital) in 2017. It's been continuously developed since 2004.
Q: How many people use CCleaner?
A: Over 2.5 billion downloads worldwide, with millions of active users. It's one of the most popular PC optimization tools globally.
Q: What platforms does CCleaner support?
A: CCleaner is available for Windows (11, 10, 8, 7), macOS (10.10 and later), and Android (5.0 and up). Each platform has a free and premium version.
Installation Questions
Q: How do I download CCleaner safely?
A: Always download from the official website: ccleaner.com or piriform.com. Avoid third-party download sites which may bundle malware or outdated versions.
Q: Does CCleaner work on Windows 11?
A: Yes, CCleaner is fully compatible with Windows 11 and receives regular updates for new Windows versions.
Q: Can I install CCleaner without admin rights?
A: No for the regular version. However, you can use CCleaner Portable which doesn't require installation or administrator privileges.
Q: Why does the installer include Google Chrome/Toolbar?
A: These are optional offers that help fund the free version. Simply UNCHECK these boxes during installation if you don't want them.
Q: How much space does CCleaner take?
A: About 50-60 MB of disk space for installation. The program itself is very lightweight.
Q: Can I install CCleaner on multiple computers?
A: Yes! The free version can be installed on unlimited personal computers. The Pro license covers 1-3 PCs depending on the plan you purchase.
Safety & Security Questions
Q: Is CCleaner safe to use in 2025?
A: Yes. While CCleaner had a security breach in 2017, it was quickly resolved. The company has since implemented better security measures, and the software is regularly audited. Always download from official sources.
Q: Will CCleaner delete my important files?
A: No. CCleaner only removes temporary files, cache, and junk. It won't delete your documents, photos, or programs unless you specifically configure it to do so.
Q: Can the registry cleaner break Windows?
A: Highly unlikely if used carefully. CCleaner creates automatic backups before registry changes and only targets safe entries. However, you should always create a system restore point before cleaning the registry.
Q: Why does my antivirus flag CCleaner?
A: Some antivirus programs show warnings because CCleaner accesses system files and makes deep changes. This is a false positive. CCleaner is safe when downloaded from the official site.
Q: Does CCleaner collect my data?
A: CCleaner collects anonymous usage data to improve the software (which you can disable in settings). It does NOT collect personal information, browsing history, or passwords.
Q: What was the 2017 security breach?
A: Hackers compromised CCleaner's build system and injected malware into version 5.33. It affected users for about 1 month before being discovered. The company responded quickly, and security has been strengthened since.
Features Questions
Q: What does the cleaner actually clean?
A: Browser cache/cookies, Windows temp files, recycle bin, Windows logs, recent file lists, memory dumps, clipboard data, and more. It supports 100+ applications.
Q: Should I clean the registry?
A: Optional. Modern Windows handles registry well. Only clean if you notice slowdowns or errors. Many experts recommend skipping registry cleaning entirely.
Q: What's the difference between Health Check and Custom Clean?
A: Health Check is automatic and beginner-friendly—one click to clean everything. Custom Clean gives you detailed control over what gets cleaned.
Q: Can CCleaner speed up my startup?
A: Yes! Use Tools > Startup to disable unnecessary programs that launch at boot. This can significantly reduce startup time.
Q: Does CCleaner work on SSDs?
A: Yes, but be careful with Drive Wiper. SSDs have limited write cycles, so don't overuse secure deletion features.
Q: Can CCleaner uninstall programs?
A: Yes. Tools > Uninstall lets you remove programs and can find leftover files that Windows Uninstaller misses.
Pricing & Versions
Q: How much does CCleaner cost?
A: CCleaner Free: $0 (forever). CCleaner Professional: $24.95/year for 1 PC. Professional Plus: $34.95/year with additional tools like file recovery and drive defragmentation.
Q: What's the difference between Free and Pro?
A: Pro adds: automatic updates, real-time monitoring, scheduled cleaning, automatic browser cleaning, duplicate file finder, and priority customer support. Free includes all core cleaning features.
Q: Is CCleaner Pro worth it?
A: If you want automation and don't want to remember to clean manually, yes. For casual users who clean monthly, the free version is usually sufficient.
Q: Can I get a refund?
A: Yes, CCleaner offers a 30-day money-back guarantee on all paid purchases.
Q: Do Pro features work offline?
A: Yes! Once activated, CCleaner Pro works fully offline. Internet is only needed for updates and initial activation.
Q: Is there a lifetime license?
A: No. CCleaner Pro is subscription-based at $24.95/year. There's no one-time payment option for the Pro version.
Usage Questions
Q: How often should I run CCleaner?
A: Weekly for most users. Daily if you browse heavily or have limited disk space. Monthly if you're a light computer user.
Q: How long does a CCleaner scan take?
A: Usually 30-60 seconds for a full scan. Cleaning takes another 10-30 seconds. Registry cleaning takes 1-2 minutes.
Q: Can I use CCleaner while other programs are running?
A: Yes, but close your browsers before cleaning them. CCleaner will notify you if it needs you to close specific programs.
Q: Should I check all the boxes in Custom Clean?
A: No! Review each option carefully. Some items (like saved passwords) you probably want to keep. Start with defaults.
Q: Can I undo CCleaner cleaning?
A: No for file cleaning—deleted files are gone (unless you use recovery software quickly). Registry changes can be restored from automatic backups.
Q: Does CCleaner need to run in the background?
A: No for Free version. Pro version can run background monitoring if you enable it, but it's optional.
Problems & Troubleshooting
Q: CCleaner won't open or crashes on startup
A: Try: 1) Run as administrator, 2) Reinstall CCleaner, 3) Check for Windows updates, 4) Temporarily disable antivirus, 5) Make sure you have .NET Framework 4.5 or later.
Q: CCleaner says my computer is out of date
A: This is a notification, not an error. It means there's a newer version available. You can update through Options > Updates or download from the website.
Q: I accidentally deleted something important
A: Use Windows File Recovery tools immediately (like Recuva by Piriform). The sooner you act, the better chance of recovery. In future, review what will be cleaned before clicking 'Run Cleaner'.
Q: CCleaner made my computer slower
A: Rare, but possible if you cleaned browser cookies and cache (sites now reload everything). Give it a few days for cache to rebuild. Check if you disabled critical startup programs.
Q: Error: 'Failed to execute script'
A: This usually means a corrupted installation. Uninstall CCleaner completely, restart PC, then reinstall from the official website.
Q: How do I restore registry backup?
A: Open CCleaner > Options > Settings > Restore (under Advanced). Select the backup date and click Restore. Only restore if you're experiencing problems after cleaning.
Technical Questions
Q: Can I use CCleaner from command line?
A: Yes! Use 'ccleaner.exe /AUTO' for silent cleaning. Many parameters available for IT administrators and power users. See CCleaner's documentation for full command-line options.
Q: Does CCleaner support silent installation?
A: Yes. Use 'ccsetup.exe /S' for silent install. Useful for deploying to multiple computers in a business environment.
Q: Can I customize what applications CCleaner cleans?
A: Yes! Go to Options > Include to add custom files/folders. You can also edit winapp2.ini for advanced customization.
Q: What is winapp2.ini?
A: An advanced configuration file that adds cleaning rules for hundreds of additional programs not included by default. Download from the CCleaner community forums.
Q: Does CCleaner have an API?
A: No official public API. For business/enterprise automation, use command-line parameters or contact CCleaner for business solutions.
Q: Can CCleaner clean network drives?
A: No. CCleaner only cleans local drives and doesn't support network paths or mapped drives for security reasons.
Still Have Questions?
Check out our detailed guides or reach out to the CCleaner community for help.