Security settings on files and folders can prevent unauthorized users from accessing data. Setting file security is appropriate for most files on the hard drive, as it adds no discernible overhead and works with little or no additional configuration. EFS protects files from intruders who have physical access to the hard drive (such as when it's stolen). Syskey provides strong protection against compromised computers, because it encrypts a great deal of the registry and helps stop an attacker from using the existing operating system. When configured correctly, the combination of file security, Syskey, and EFS helps to ensure that only authorized users may access data.