I worked on a customer home desktop recently that had CCleaner on it. Glary Utilities Free does everything that commenters here write about CCleaner but with a much simpler, easy-to-use interface. I routinely use it to untangle the registry, delete temp files, update startup items and even find malware (before a full scan with AdAware if no other AV is installed) with GUs 1-Click Maintenance. I have not had a problem yet with it on customer computers or my own desktop. Plus, GU has a Memory Optimizer that frees RAM that is no longer being used on a real-time basis. I set it and the GU main window to open on Windows startup. Like doing a hard drive wipe without losing any programs, settings or files!