Core Operating System

Applies To: Windows Server 2008 R2

Core Operating System includes the components that support the services that perform basic device management for Windows. These components include Display Drivers, Plug and Play Devices, Name resolution for peer communication, and Service Control Manager.

Hierarchy of Managed Entities

Managed Entities

Name Description

Display Driver Models

The Windows operating systems support a well documented, standard architecture for implementing device drivers for graphics adapters. With this model, neither the applications running on your computer nor the operating system itself need to know the details of any particular graphics adapter.  Instead, Windows sends high-level commands to the device driver provided by the manufacturer of the graphics adapter. The device driver, in turn, advertises the capabilities of the graphics adapter to Windows. The device driver translates the commands into the device-specific operations to cause the display output to show what Windows requested.

Windows Display Driver Model

Microsoft Windows Vista and Windows Server 2008 introduce a new, more advanced driver model for display and graphics hardware called the Windows Display Driver Model (WDDM). To see many of the advanced video capabilities of Windows Vista, such as the Aero desktop theme, you must be using a graphics card that uses a WDDM-compatible device driver. Graphics adapters that use the older Windows XP Display Driver Model (XPDM) still work in Windows Vista and Windows Server 2008, but they cannot take advantage of the advanced video features that a WDDM driver can.

For more information about the Windows Display Driver Model, see on the Microsoft Web site.

Windows XP Display Driver Model

The Windows XP Display Driver Model (XPDM) is the display driver model used in the Windows XP and Windows 2000 operating systems. XPDM device drivers can be used in Windows Vista and Windows Server "Longhorn" operating systems, but cannot be used to enable the advanced features of Windows Vista, such as the Aero desktop theme.

User Plug and Play

The Plug and Play system in Windows is responsible for the installation of devices. Plug and Play records the result of a device installation on a computer as an event log entry. A device installation in Windows includes the installation of a device driver and might also include a service that supports the operation of the device.

Peer Name Resolution Protocol (PNRP) Client

Peer Name Resolution Protocol (PNRP) is used by Windows Peer-to-Peer Networking to resolve names for peer communication.

In peer-to-peer environments, peers rely on name resolution systems to resolve each other's network locations (addresses, protocols, and ports) from names or other types of identifiers. PNRP provides a secure, scalable, and dynamic name registration and name resolution protocol first developed for Windows XP, and then upgraded in Windows Vista and Windows Server 2008. PNRP works very differently from traditional name resolution systems, opening up new possibilities for applications.

PNRP has the following properties:

  • Distributed and serverless for scalability and reliability
  • Effortless name publication without using third party applications 
  • Real time updates to identifiers and addresses.
  • Identifies more than just computers
  • Protected name publication (secure and non-secure name publication)

Service Control Manager

The Service Control Manager (SCM) maintains a database of the installed services and driver services that allow the operating system to start successfully, and provides a unified and secure means of controlling them. The database, which is stored in the Windows system registry, includes configuration and security information about each service or driver service.

System administrators should use the Services snap-in or the sc.exe command-line tool to query or configure services. It is not recommended to directly alter or read the SCM database present in the registry.

For more information about the Windows Services infrastructure, see For more information about Service Control Manager and the SC command, see and

Service Events Logging

The Service Control Manager (SCM) logs service events to record the activity within a service, for example, the successful start of a service or the unexpected termination of a service.

Windows Customer Experience Improvement Program

The Windows Customer Experience Improvement Program (CEIP) collects information about how you use Microsoft programs and about some of the problems you encounter. Microsoft uses this information to improve the products and features you use most often and to help solve problems. Participation in the program is strictly voluntary, and the end results are software improvements to better meet your needs.

For more information about exactly what types of data CEIP collects and uploads, see the Microsoft Customer Experience Improvement Program Web site (