Spy Sweeper is proprietary software sol by Webroot Software, which detects and removes spyware, and viruses (optional component) on personal computers that run Microsoft Windows. It examines files on a computer's hard disk drive, as well as objects in memory, the Windows registry and cookies, and quarantines any suspicious objects it finds. Spy Sweeper runs continuously while the computer is in operation, monitoring to warn the user of programs being set to start automatically, suspicious programs running, malicious website cookies, unwanted Internet Explorer changes, known adware websites, suspicious executable files, ActiveX installations and changes, and changes in system services. It is normally purchased as a yearly subscription; some broadband services, such as MSN Premium, also offer rebranded versions of Spy Sweeper as part of their subscription.