CCleaner stopped working after Win11 update — any fixes people recommend?

After a Windows 11 update, CCleaner can stop working because system libraries or permissions change, so the app can’t launch or scan properly.

A reliable first step people recommend is updating CCleaner to the latest version and installing it fresh. Even if it looks installed, the update can restore compatibility with the newest Windows build.

If updating doesn’t help, run CCleaner as Administrator (right-click → Run as administrator), because recent updates tighten app permissions, and elevated access often fixes launch/crash issues.

Another widely recommended trick is temporarily disabling Windows Defender real-time protection or third-party antivirus, since security tools can block CCleaner’s file access after a major OS update.

Some users also find that installing the CCleaner Portable version bypasses registry/permission conflicts introduced by the update, letting scans run cleanly without breaking shortcuts or services.

These are key methods that we can offer. If you have more, please share.