Plug and Play Manager
The Plug and Play (PnP) manager provides the support for PnP functionality in Windows and is responsible for the following PnP-related tasks:
Device detection and enumeration while the system is booting
- Adding or removing devices while the system is running
The PnP manager consists of the following components:
- Kernel-mode PnP manager
The kernel-mode PnP manager notifies the user-mode PnP manager that a new device is present on the system and must be installed.
- User-mode PnP manager
The user-mode PnP manager receives device installation requests from the kernel-mode PnP manager, calls other user-mode components to start device installation tasks, and sends control requests (such as "start the device") to the kernel-mode PnP manager.
The user-mode PnP manager tries to install a device in a trusted process context without requiring users to respond to dialog boxes. This method is known as a server-side installation.
The PnP manager maintains the Device Tree that keeps track of the devices in the system. The device tree contains information about the devices present on the system. When the computer starts, the PnP manager builds this tree by using information from drivers and other components, and updates the tree as devices are added or removed.