CleanGeek clears out temp files, browser caches, log files and Windows update leftovers. No registry cleaner, no scare screens, no paid upgrade. It shows you exactly what it will remove before it removes it, and it runs entirely on your machine.
Every free PC cleaner I tried had the same problem. A registry cleaner nobody needs, a scary red count of "issues", and a paid version dangled at the end. I wanted the boring version: show me the temp folders, the browser caches, the log files and the Windows update leftovers, tell me how much space each one is worth, and let me untick anything I want to keep.
That is all CleanGeek does. Nothing is deleted until you press the button, nothing leaves your machine, and there is no paid tier to upgrade to. It is free and the source is on GitHub.
One honest caveat: the installer is not code signed yet, so SmartScreen may warn on first run.
Happy to hear what it misses on your machine.