I depend heavily on it, and wouldn't be without it. The important observation is this: CCleaner comes with many, many default settings that might very well F-up your computer, so the way to use it successfully is to use it conservatively. I use the Custom Clean function (with fewer than a dozen entries checked), the Registry checker (with only five entries checked), and the Tools > System Restore list (which lets me efficiently delete older, unnecessary Restore Points) only. They serve me extremely well, and efficiently, too. I wouldn't advise using the Health Check, the Driver Updater, or the Optimizer. They can, indeed, cause damage. Fortunately, CCleaner offers rollback functions for most of the things it does, and if you choose to delete some registry entries with it, you can (and should) opt to file a backup of the registry settings it changes for you. That way, if anything doesn't please you, you can restore the registry to the state it was in before you deleted anything. As for the uninstaller in CCleaner, Revo does a better job, so I don't use the CCleaner version of that, either.
