Extended System Configuration Data


Extended System Configuration Data (ESCD) is a section of non-volatile BIOS memory where data about the system’s hardware configuration is stored. It was developed for use in Plug and Play BIOSes to store resource information for non PnP (Plug and Play) devices. Updates to it are automatically handled by the system BIOS.


The phonetics for the keyword “Extended System Configuration Data” would be:Extended: /ɪkˈstɛndɪd/System: /ˈsɪstəm/Configuration: /kənˌfɪgjʊˈreɪʃən/Data: /ˈdeɪtə/ or /ˈdɑːtə/ Please note that the pronunciation of some words, including “data”, can vary based on regional dialects.

Key Takeaways

Extended System Configuration Data

Three Main Takeaways about Extended System Configuration Data:

  1. Complex System Data: Extended System Configuration Data provides a comprehensive record of a PC’s hardware and software. It records complex system data including information about the operating system, connected hardware, installed programs, network details, and more.
  2. Problem Diagnosis and System Management: With the rich detail that Extended System Configuration Data provides, it helps users or IT administrators diagnose problems, manage systems, and perform routine maintenance. It is a crucial tool for understanding the overall health and functionality of a system.
  3. Interoperability and Comptability: Extended System Configuration Data allows for improved interoperability and compatibility of hardware and software systems by providing clear and accurate system details. It aids in ensuring all components of a system will work together efficiently and effectively.


Extended System Configuration Data (ESCD) is a crucial technology term as it refers to an area in a computer’s non-volatile memory where data about the system’s Plug-and-Play devices is stored. This data includes information about the resource assignment of these devices such as I/O ports, memory address space, interrupt levels and direct memory access (DMA) channels. With this information, the system can quickly initialize each device upon startup without going through an extensive discovery process. The ESCD therefore contributes to overall system efficiency and performance and simplifies device management in the Plug-and-Play system.


Extended System Configuration Data (ESCD) plays a significant role within computer systems, particularly regarding peripheral device support. As a data storage tool, its purpose is to ensure that the system’s BIOS (Basic Input/Output System) can remember the profile and necessary resources of the peripherals, even after being turned off or rebooted. This essentially makes for a faster, seamless system startup because the BIOS does not need to re-identify the hardware and assign resources each time during the boot process. It serves to make computer systems more efficient, particularly those with numerous peripherals linked up to them.The ESCD holds information about how your computer’s hardware (like printers, scanners, keyboards, or mouse) is configured and how they’re integrated into the system. This function is crucial, especially for Plug and Play (PnP) systems, because it allows hardware changes or new hardware additions to be easily identified and configured by the BIOS. By having a repository of the system’s hardware configuration, it enables easier troubleshooting if any device issues arise. Hence, ESCD enables smoother operation of the system by supporting effective communication between the system and its peripherals.


1. BIOS Firmware: Almost all modern computing devices have BIOS firmware in which the Extended System Configuration Data (ESCD) is stored. This data provides information and instructions on how startup or booting processes should interact with the hardware resources plugged into system like data about the state of motherboard slots, IRQs, DMAs, I/O port addresses etc.2. Plug and Play (PNP) Devices: In older versions of operating systems like Windows 95/98, any new hardware device installed in the computer required an extension of the system configuration data. Using PNP technology, the device and the operating system communicated and new ESCD was created and stored in non-volatile memory for future boot-ups.3. Servers: Many modern servers use ESCD to manage system configurations, identifying and organising the hardware resources necessary for system functioning. This includes information about MultiProcessor Specification (MPS) for multiprocessor motherboards or Advanced Configuration and Power Interface (ACPI) data for power management capabilities.

Frequently Asked Questions(FAQ)

**Q: What is Extended System Configuration Data (ESCD)?**A: Extended System Configuration Data, also known as ESCD, is a memory space used by BIOS to store data about the configuration of an installed device. It is specifically used to store information about Plug and Play (PnP) devices.**Q: What is the main purpose of ESCD?**A: The primary use of ESCD is to store configuration data for all PnP devices. This information helps the system remember the proper configuration for these devices between system boots.**Q: Is ESCD only used for Plug and Play (PnP) devices?**A: Yes, the ESCD is specifically designed to store configuration data for PnP devices. Non-PnP devices have their configurations stored elsewhere in the BIOS.**Q: Can ESCD data be modified?**A: Typically, ESCD data is managed and updated by the system BIOS automatically. However, in some circumstances such as troubleshooting device conflicts, a user or technician may need to manually reset or modify this data.**Q: How can I modify the ESCD data manually?**A: The process to modify ESCD data manually can vary based on your system’s BIOS. However, it typically involves entering the BIOS setup during system boot, finding the relevant settings (often labeled as “Reset Configuration Data” or something similar), and enabling the reset. After saving changes and rebooting, the BIOS should clear and rebuild the ESCD.**Q: What happens if the ESCD data is lost or corrupted?**A: In case your ESCD data becomes lost or corrupted, the system BIOS should be able to rebuild it by detecting all PnP devices during boot and reconstructing the necessary information.**Q: How is ESCD different from CMOS?**A: While both the ESCD and the CMOS are used for storing system configuration data, the primary difference is in what they store. The CMOS holds data about the system clock and other non-PnP hardware settings, while the ESCD specifically holds data about the PnP configurations.

Related Finance Terms

  • BIOS (Basic Input/Output System)
  • CMOS (Complementary Metal-Oxide-Semiconductor)
  • Firmware
  • System Boot Process
  • Non-Volatile RAM (Random Access Memory)

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