CCleaner (or Crap Cleaner) is a very effective tool in removing unnecessary files from your hard drive to free up disk space. You check what categories you want cleaned, such as certain browser files, the temp directory, log files for various applications, etc, so you have control over what is actually removed. CCleaner supports the cleaning of files from several programs. Ccleaner contains an “Analyze” button so you can see what files will be removed before actually running the cleaner. Unfortunately, CCleaner does not give you the ability to uncheck a certain file from a category. It's either all or none.
CCleaner also contains a registry cleaner. It's fairly effective in removing unneeded registry entries which could potentially slow down your system. The only problem I've had with using the registry cleaner is when the “Unused File Extensions” box is checked. Checking this has led my computer to have issues, as such, I now always leave it unchecked. On the plus side, unlike the file cleaner, the registry cleaner does allow you to uncheck values you don't want removed. It also asks if you want to backup the registry before running the cleaner.
Aside from the two main features, CCleaner also has a startup manager and program uninstaller allowing. As CCleaner loads installed programs faster, it's a faster way to uninstall programs. The startup manager allows for the disabling/enabling of programs from starting up at the computer's start and allows for the removal of the startup entry from the registry entirely.
Exempt Cookies – a list of browser cookies you never want deleted.
Include/Exclude Files/Folders – Allows for the inclusion/exclusion of files/folders to be removed/cleaned.