Class installers are dynamic-link libraries that install, configure, and remove devices or classes of devices in the system. Windows NT provides a set of default installers that can be used to install devices belonging to the default classes. If your class of device has features that are not supported by the default installers, you can create a new installer for your class and direct the system to use that installer whenever the user installs that particular class of device. Additionally, Windows NT supports a set of default device installation requests that can be used on a device of any class.