“"I've been using it since it came out... default setting on cleaning unused files you're going to be plenty safe." — Community user on Reddit ” Reddit · r/computer · 1 year ago

Patented technology that puts inactive apps to sleep to free up system resources.

A major security breach occurred where a specific version was compromised with malware. Experts at Wikipedia note that this issue was corrected in all subsequent releases.

Scans for and updates outdated hardware drivers to improve stability.

“"It's more important that the app does the job you're paying hard earned money for and that's certainly the case in our testing..." — Tech Advisor ” Tech Advisor · 2 years ago

CCleaner 6.09 (and more broadly the version 6 series) is a comprehensive PC optimization utility that remains a solid choice for users seeking an "all-in-one" solution, though its status as a "must-have" has diminished due to modern Windows features. The version you mentioned, often packaged in .7z archives on various sites, typically refers to the Professional or Business editions, which include automated cleaning and performance-boosting features not found in the free version. Key Features and Performance

These videos provide a deeper look into CCleaner's features, comparing the Free and Professional versions and exploring modern alternatives: CCleaner 6 Review: An Essential Tool for Windows Users YouTube · Make Tech Easier CCleaner Pro vs Free | Which is Best for You? 2026 YouTube · HowToHarbor