Get the Shared Computer Toolkit

Microsoft's new utility for managing and securing computers that are shared among multiple users was designed with public computers (in schools, libraries, Internet cafes, etc.) in mind. However, the toolkit also has features that make it useful for managing "family" computers, including controls that make it easy to prevent children from accessing certain programs such as Windows Messenger or from changing the computer's configurations or running inappropriate programs, and even lets you apply a session timer to a child's computer use to control the amount of time kids can spend on the computer. The beta is a free download and you can read more about it here.