CCleaner 7 won’t open on my PC — how can I resolve this?

If CCleaner 7 won’t open at all, the most common cause is a corrupted install or a conflict with Windows security features.

Uninstall CCleaner completely, reboot, then reinstall the latest CCleaner 7 build from the official Piriform/CCleaner website and run it once as administrator.

Windows Defender or third-party antivirus software can silently block CCleaner at launch, especially after major updates.

Temporarily disable real-time protection or add CCleaner to the antivirus exclusions list, then try opening it again.

Another frequent issue is compatibility with older Windows builds or missing system components.

Make sure your Windows version is fully updated and that you have the latest Visual C++ Redistributables installed, as CCleaner depends on them.

This is the information we have, but if you have more insights from your experience, please share in the comments.