Ntdetect.com
Encyclopedia
ntdetect.com is a component of Microsoft Windows NT-based operating system
s that operate on the x86 architecture. It is used during the Windows NT startup process
, and is responsible for detecting basic hardware that will be required to start the operating system
.
Though it has the .COM
extension, it is not actually a DOS application.
Ntdetect.com is invoked by NTLDR
, and returns the information it gathers to NTLDR when finished, so that it can then be passed on to ntoskrnl.exe
, the Windows kernel.
Ntdetect.com is used on computers that use BIOS
firmware. Computers with Extensible Firmware Interface
, such as IA-64, use a method of device-detection that is not tied to the operating system.
Hardware detection operates somewhat differently depending on whether or not Advanced Configuration and Power Interface
(ACPI) is supported by the hardware. It passes on the hardware details gathered from the BIOS onto the OS. If ACPI is supported, the list of found devices is handed to the kernel, Windows will take responsibility for assigning each device some resources. On older hardware, where ACPI is not supported, the BIOS
takes responsibility for assigning resources, not the operating system, so this information is passed to the kernel as well.
In addition, ntdetect.com will make a determination as to which hardware profile to use. Windows supports multiple distinct hardware profiles, which allows a single copy of Windows to work well in situations where the hardware changes between specific layouts on a regular basis. This is common with portable computers that connect to a docking station
.
In Windows Vista
and later Windows operating systems, ntdetect.com only supports ACPI, so that Windows will be able to control hardware resource allocation on every machine in the same way. Hardware profiles are also no longer supported in Windows Vista.
The information gathered by ntdetect.com is stored in the
at a later stage in the boot process.
.
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
s that operate on the x86 architecture. It is used during the Windows NT startup process
Windows NT Startup Process
The Windows NT startup process is the process by which Windows NT 4.0, Windows 2000, Windows XP and Windows Server 2003 operating systems initialize...
, and is responsible for detecting basic hardware that will be required to start the operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
.
Though it has the .COM
.com
The domain name com is a generic top-level domain in the Domain Name System of the Internet. Its name is derived from commercial, indicating its original intended purpose for domains registered by commercial organizations...
extension, it is not actually a DOS application.
Overview
The bootstrap loader takes the control over the booting process and loads NTLDR.Ntdetect.com is invoked by NTLDR
NTLDR
NTLDR is the boot loader for all releases of Windows NT operating system up to and including Windows XP and Windows Server 2003. NTLDR is typically run from the primary hard disk drive, but it can also run from portable storage devices such as a CD-ROM, USB flash drive, or floppy disk...
, and returns the information it gathers to NTLDR when finished, so that it can then be passed on to ntoskrnl.exe
Ntoskrnl.exe
ntoskrnl.exe is the kernel image for the family of Microsoft Windows NT operating systems...
, the Windows kernel.
Ntdetect.com is used on computers that use BIOS
BIOS
In IBM PC compatible computers, the basic input/output system , also known as the System BIOS or ROM BIOS , is a de facto standard defining a firmware interface....
firmware. Computers with Extensible Firmware Interface
Extensible Firmware Interface
The Unified Extensible Firmware Interface is a specification that defines a software interface between an operating system and platform firmware...
, such as IA-64, use a method of device-detection that is not tied to the operating system.
Hardware detection operates somewhat differently depending on whether or not Advanced Configuration and Power Interface
Advanced Configuration and Power Interface
In computing, the Advanced Configuration and Power Interface specification provides an open standard for device configuration and power management by the operating system....
(ACPI) is supported by the hardware. It passes on the hardware details gathered from the BIOS onto the OS. If ACPI is supported, the list of found devices is handed to the kernel, Windows will take responsibility for assigning each device some resources. On older hardware, where ACPI is not supported, the BIOS
BIOS
In IBM PC compatible computers, the basic input/output system , also known as the System BIOS or ROM BIOS , is a de facto standard defining a firmware interface....
takes responsibility for assigning resources, not the operating system, so this information is passed to the kernel as well.
In addition, ntdetect.com will make a determination as to which hardware profile to use. Windows supports multiple distinct hardware profiles, which allows a single copy of Windows to work well in situations where the hardware changes between specific layouts on a regular basis. This is common with portable computers that connect to a docking station
Docking station
A Docking station or port replicator or dock provides a simplified way of “plugging-in” an electronic device such as a laptop computer to common peripherals...
.
In Windows Vista
Windows Vista
Windows Vista is an operating system released in several variations developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs...
and later Windows operating systems, ntdetect.com only supports ACPI, so that Windows will be able to control hardware resource allocation on every machine in the same way. Hardware profiles are also no longer supported in Windows Vista.
The information gathered by ntdetect.com is stored in the
HKLM\HARDWARE\DESCRIPTION key in the Windows RegistryWindows registry
The Windows Registry is a hierarchical database that stores configuration settings and options on Microsoft Windows operating systems. It contains settings for low-level operating system components as well as the applications running on the platform: the kernel, device drivers, services, SAM, user...
at a later stage in the boot process.
Classes of hardware detected
- Hardware identification
- Hardware date & time
- Bus and adapter types
- SCSISCSISmall Computer System Interface is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, and electrical and optical interfaces. SCSI is most commonly used for hard disks and tape drives, but it...
adapters - Video adapters
- Keyboard
- Serial and parallel communication ports
- Hard drives
- Floppy disks
- Mouse
- Floating-point coprocessorCoprocessorA coprocessor is a computer processor used to supplement the functions of the primary processor . Operations performed by the coprocessor may be floating point arithmetic, graphics, signal processing, string processing, or encryption. By offloading processor-intensive tasks from the main processor,...
- [Industry Standard Architecture]-based devices
Troubleshooting
To aid in troubleshooting, Microsoft has made available "debug" versions of ntdetect.com which will display detailed information about the hardware that was detected. Called ntdetect.chk, it is included in the Windows Support ToolsWindows Support Tools
Windows Support Tools is a suite of management, administration and troubleshooting tools for Microsoft Windows 2000, Windows XP, Windows Server 2003 and Windows Server 2003 R2 from Microsoft Corporation....
.
External links
- Download of ntdetect.chk for Windows 2000
- Windows XP SP2 Support Tools includes ntdetect.chk for Windows XPWindows XPWindows XP is an operating system produced by Microsoft for use on personal computers, including home and business desktops, laptops and media centers. First released to computer manufacturers on August 24, 2001, it is the second most popular version of Windows, based on installed user base...
. - Troubleshooting Windows NT Boot Failures