Plug a USB device into your computer, and then visit the "CCleaner - Builds" Web page (link in Resources). Click the "Download" button in the page's "CCleaner - Portable" section.

Before deleting, CCleaner gave a clear warning that the files would be permanently removed, and asked for confirmation. Most ...

CCleaner also includes a registry scanner, startup manager, and Add/Remove Programs area to uninstall applications you don't use anymore. CCleaner 2.0 is a free download for Windows only.

The free version of CCleaner shows adverts and starts with Windows without a deactivation option. We will show you how to prevent the autostart anyway.

The malicious program was slipped into legitimate software called CCleaner (pictured) created by London-based company Piriform, which is downloaded as often as five million times a week.