Glossary of Terms

Term Definition

$OEM$ Folders

A folder that includes additional files for the Windows installation.


The path and folder name where the Windows system files are located. Typically, this is C:\Windows. This is identical to the %WINDIR% variable.


The default directory where Windows is installed, most commonly C:\Windows.

.cab file

Cabinet file. A single file that stores multiple compressed files. These files are commonly used in software installation and to reduce the file size and the associated download time for Web content.

.dll file

See Other Term: dynamic-link library (DLL)

.ini file

Initialization file used by the operating system and by individual applications to store persistent settings related to applications, drivers, or hardware. Supported for backward compatibility. Use the registry to store these settings.

.iso file

An image file typically used to create optical disks including CD-ROMs and DVDs.

.swm file

See Other Term: split Windows imaging file (.swm)

.vhd file

See Other Term: virtual hard disk

.wim file

A Windows image file, which can contain one or more Windows images.


See Other Term: Advanced Configuration and Power Interface (ACPI)


A process that reduces Windows piracy by ensuring compliance with Microsoft Software License Terms. During product activation, the product key is matched with the individual computer on which the software is installed. It does this by validating the product key and checks that it has not been used with more than the licensed number of computers.

active partition

A type of partition that enables an operating system to boot. The active partition must be a primary partition on a basic disk. If you use Windows exclusively, the active partition can be the same as the system volume.


A set of technologies that allows software components to interact with one another in a networked environment, regardless of the language in which the components were created.

Advanced Configuration and Power Interface (ACPI)

An open industry specification that defines power management on a wide range of mobile, desktop, and server computers and peripherals. ACPI is the foundation for the OnNow industry initiative that allows system manufacturers to deliver computers that start at the touch of a keyboard. ACPI design is essential to take full advantage of power management and Plug and Play.

answer file

An XML file that contains the settings and configurations to apply to a Windows image during installation. The answer file for Windows Setup is commonly called Unattend.xml. You can create and modify this answer file by using Windows System Image Manager (Windows SIM) or the CPI APIs.


See Other Term: application programming interface (API)

application programming interface (API)

A set of routines that an application uses to request and carry out services performed by the application or operating system.


To mount a virtual hard disk. The virtual hard disk is activated, such that it appears on the host computer as a disk drive, rather than as a .vhd file.

audit mode

A stage of Windows Setup that enables additional customization and testing prior to deployment. Audit mode replaces Factory mode in Windows XP.

authorized distributor

An independent company licensed by Microsoft Licensing, GP or Microsoft Ireland Operations, Ltd. to manage the production and distribution of multipacks of Windows OEM products to system builders. If you purchase Microsoft software from someone other than a Microsoft authorized distributor, you run the risk of purchasing counterfeit software, which usually has many of the following problems: missing drivers, missing documentation, viruses, bugs, and other defects. Installing legitimate Microsoft products prevents customer problems and reduces requests for customer support.

authorized replicator

An independent company licensed by Microsoft Licensing, Inc., to manage the production and distribution of Microsoft OEM products for royalty OEMs. Microsoft Licensing, Inc., supplies the authorized replicator with the master components, manufacturing and assembly specifications, and other pertinent instructions. The authorized replicator manufactures and assembles genuine Microsoft products to exact specifications. The benefits of using an authorized replicator include protection against piracy, consistent high-quality software, and competitive prices.


An unattended-setup component that automatically provides account credentials to log on to Windows when the computer restarts.

basic volume

A primary partition or logical drive that resides on a basic disk.


See Other Term: Boot Configuration Data (BCD)

Boot Configuration Data (BCD)

A data store that contains boot configuration parameters and controls how the operating system is started in Windows. The objects and elements in the data store replace the Boot.ini file in Windows XP.

boot partition

The partition that contains the Windows operating system and its support files. The boot partition can be, but does not have to be, the same as the system partition.

boot-critical driver

A driver that must be available for the operating system to successfully boot.


To manufacture a computer according to a customer's specification.


To manufacture a computer according to a preconfigured specification.


A binary file that contains the state of all of the settings and packages in a Windows image. When a catalog is created, it queries the Windows image for a listing of all of the settings in that image. Because the contents of a Windows image can change over time, it is important that you recreate the catalog file whenever you update a Windows image.

clean installation

The process of installing Windows onto a computer that does not have an operating system installed or overwriting an existing operating-system installation. Clean installations do not automatically migrate data from previous installations.


A part of the Windows operating system that specifies the files, resources, and settings for a specific feature or part of a feature. Components are dependent on one another or are required for Windows to function. Windows unattended-installation settings can be used by OEMs and corporations to customize components.

Component Platform Interface (CPI)

A programming interface used to build and maintain unattended-installation answer files and configuration sets by adding security fixes, changing drivers, and so forth.

configuration pass

A phase of Windows installation. Different parts of the Windows operating system are installed during different configuration passes. You can specify Windows unattended-installation settings to be applied during one or more configuration passes.

configuration set

A folder structure that contains the files that control preinstallation.


See Other Term: build-to-order


See Other Term: Component Platform Interface (CPI)

custom installation

The process of configuring a computer for a clean Windows installation. This includes disk configuration, image selection, and other preinstallation options.

data image

A .wim file that you can add applications, files, scripts, and other resources to during a Windows installation.

destination computer

A computer that you distribute to end users.

Device Manager

An administrative tool that you can use to manage the devices on your computer. Using Device Manager, you can view and change device properties, update device drivers, configure device settings, and uninstall devices.

distribution share

A folder that contains the source files for Windows products that you install. It may also contain additional device drivers and application files. This folder can be created manually or by using Windows System Image Manager (Windows SIM).

dynamic volume

A volume that resides on a dynamic disk. Windows supports five types of dynamic volumes: simple, spanned, striped, mirrored, and RAID-5. A dynamic volume is formatted by using a file system, such as file allocation table (FAT) or NTFS, and has a drive letter assigned to it.

dynamic-link library (DLL)

An operating system feature that allows executable routines (generally serving a specific function or set of functions) to be stored separately as files with .dll extensions. These routines are loaded only when needed by the program that calls them.


A collection of extensible user interface areas that are shared between Windows and OEMs. These user interface areas enable OEMs to differentiate brand identity, present monetization opportunities, and reduce costs through customizations.


See Other Term: Extensible Firmware Interface (EFI)

Emergency Management Services (EMS)

Services that enable the administrator to interact with a computer that might not be available through the usual network mechanisms. For example, administrators can restart computers, or start and stop processes and services by using EMS.


See Other Term: Emergency Management Services (EMS)

end user

The person who ultimately receives the computer manufactured by the OEM or corporation.

extended partition

A type of partition that you can create only on basic master boot record (MBR) disks. Extended partitions are useful if you want to create more than four volumes on a basic MBR disk. Unlike primary partitions, you do not format an extended partition with a file system and then assign a drive letter to it. Instead, you create one or more logical drives within the extended partition. After you create a logical drive, you format it and assign it a drive letter. An MBR disk can have up to four primary partitions or three primary partitions, one extended partition, and multiple logical drives.

Extensible Firmware Interface (EFI)

A type of interface between a computer, firmware, hardware, and the operating system. EFI defines a new partition style called GUID partition table (GPT). EFI serves the same purpose as the basic input/output system (BIOS) found in most x86-based computers.


See Other Term: file allocation table (FAT)


A derivative of the file allocation table (FAT) file system. FAT32 supports smaller cluster sizes and larger volumes than FAT, which results in more efficient space allocation on FAT32 volumes.

file allocation table (FAT)

A file system used by MS-DOS and other Windows operating systems to organize and manage files. The file allocation table is a data structure that Windows creates when you format a volume by using FAT or FAT32 file systems. Windows stores information about each file in the file allocation table so that it can retrieve the file later.

first boot

A phase of Windows Setup. First boot starts the first time an end user boots Windows.

first-run experience

See Other Term: Windows Welcome

free space

Available space that you use to create logical drives within an extended partition.


A customizable program that displays continuously updated information on Windows Sidebar. Examples are clocks, news headlines, slide shows, and weather forecasts. Also, an add-in program that runs on a Windows SideShow–compatible device and updates the device with information from the local computer, such as e-mail messages.

Getting Started

A feature that serves as a launching point for several optional Windows tasks and OEM-defined tasks.


See Other Term: GUID partition table (GPT)

GUID partition table (GPT)

A disk-partitioning scheme that is used by the Extensible Firmware Interface (EFI). GPT offers more advantages than master boot record (MBR) partitioning.


See Other Term: hardware abstraction layer (HAL)

hardware abstraction layer (HAL)

A thin layer of software provided by the hardware manufacturer that hides, or abstracts, hardware differences from higher layers of the operating system. By means of the filter provided by the HAL, different types of hardware look alike to the rest of the operating system. This enables the operating system to be portable from one hardware platform to another. The HAL also provides routines that enable a single device driver to support the same device on all platforms.

Help and Support Center

A unified place where a user can access all Help and Support content and services from Microsoft, the OEM, and the corporation.


A single, cumulative package composed of one or more files used to address a problem in a product. Hotfixes address a specific customer situation and may not be distributed outside the customer organization.


Hyper-V is a role in Windows Server 2008 that includes tools and services that can be used to create a virtualized server environment.


The hypervisor is a layer of software that runs above the physical hardware and below one or more operating systems. It is the platform that virtual machines are run on in Windows Server 2008.


See Other Term: independent hardware vendor (IHV)

independent hardware vendor (IHV)

A company that manufactures hardware devices and the associated device drivers.

independent software vendor (ISV)

An individual or an organization that independently creates computer software.

input locale

A setting that contains a language and an input method.


See Other Term: independent software vendor (ISV)


The combination of a 64-bit Windows operating system and a microprocessor that natively supports the Intel 64-bit (IA 64) instruction set.

kernel mode

A highly privileged mode of operation where program code has direct access to all memory, including the address spaces of all user-mode processes and applications, and to hardware. Also known as supervisor mode, protected mode, or Ring 0.

language for non-Unicode programs

The default code pages and associated bitmap font files for a specific computer and all of that computer's users. The default code pages and fonts enable a non-Unicode application written for the language version of one operating system to run correctly on an operating system with another language version.

Language Interface Pack (LIP)

A localized language pack that includes less than 100 percent of the resources. LIPs can be installed only on top of a fully localized language pack.

language pack

A package that contains the files, fonts, and other resources for a specific language and locale. There are two types of language packs: a fullly localized language pack that contains 100 percent of the resources for a language and a locale and a partially localized language pack that contains less than 100 percent of resources.


See Other Term: Lightweight Directory Access Protocol (LDAP)


The right of a person or entity to use software in a particular way, as described in the terms of the license agreement. Copyright law also limits how a person may use the software. A person needs a license agreement for each software program they use.

Lightweight Directory Access Protocol (LDAP)

The primary access protocol for Active Directory. LDAP is an industry-standard protocol, established by the Internet Engineering Task Force (IETF), that allows users to query and update information in a directory service. Active Directory supports both LDAP version 2 and LDAP version 3.


See Other Term: Language Interface Pack (LIP)


A collection of rules and data specific to a language and a geographic area. Locales include information about sorting rules, date and time formatting, numeric and monetary conventions, and character classification.

mass-storage device

A generic term for disk, optical disk, or other device that provides persistent storage for computer data.

master boot record (MBR)

The first sector on a hard disk, which begins the process of starting the computer. The MBR contains the partition table for the disk and a small amount of executable code called the master boot code.

MFU list

Most Frequently Used list. A list of applications that the end user has recently used or uses frequently.

Microsoft Reserved (MSR) partition

A required partition on every GUID partition table (GPT) disk. System components can allocate portions of the MSR partition to new partitions for their own use.

Microsoft Software License Terms

A legal agreement between Microsoft and the end user, regarding the terms of use and transfer of software.

mount point

See Other Term: volume mount point

native boot

An operating-system installation and configuration that uses a virtual hard disk as the running operating system. There is no host operating system or hypervisor in a native-boot configuration.

notification area

The area on the taskbar adjacent to the system control area that contains icons that appear when certain events occur, such as when you receive e-mail.

NTFS file system

A means of formatting hard disks so they can store information. NTFS provides several improvements over earlier file allocation table (FAT) file systems, including file and folder permissions, encryption, and file compression.

OEM Activation

Technology that provides royalty OEMs with the ability to pre-activate copies of Windows and helps prevent the copying of legitimately licensed operating-system software onto nonlicensed computers by associating the operating system with the computer hardware.

OEM branding

A company name, logo, support information, and Help files in a Windows installation.

offline servicing

The process of installing packages and other updates to a Windows image that is not currently running. For example, you can update a Windows image on another partition with security updates, language packs, or other packages.

online servicing

The process of installing packages and other updates to a Windows image that is currently running.


See Other Term: Windows Welcome


A file that stores content to display in the customizable areas of Windows Welcome, the OEM First Run application, and the Network and Sharing Center Control Panel.

Out-Of-Box Experience (OOBE)

See Other Term: Windows Welcome


A group of files that modify Windows features. Package types include service packs, security updates, language packs, and hotfixes.

Package Manager

Superceeded by DISM in Windows 7. A tool that installs, uninstalls, configures, and updates features and packages.

plug and play

A type of device, such as a game controller or printer, that automatically works when you connect it to your computer. The computer configures the settings and installs the necessary drivers automatically.

Preboot Execution Environment (PXE)

A remote boot technology based on Dynamic Host Configuration Protocol (DHCP) that is used to start or install an operating system on a client computer from a remote server. A Windows Deployment Services (WDS) Server is an example of a PXE Server.

primary partition

A type of partition created on basic disks that can host an operating system and functions as though it were a physically separate disk. Also called a volume. Up to four primary partitions can be created on a basic disk.

product key

A sequence of 25 letters and numbers used to activate Windows. The product key sticker is on the back of the installation CD or DVD cover, on the back of the Windows manual, or on the back of the computer.


See Other Term: Preboot Execution Environment (PXE)

reference computer

The computer that contains your reference image.

reference image

A configured Windows image that includes additional software applications and updated drivers. A single reference image can be deployed to multiple destination computers.

Remote Installation Services (RIS)

After Windows XP, this was replaced by Windows Deployment Services.

security ID (SID)

A data structure of variable length that identifies user, group, and computer accounts. Every account on a network is issued a unique SID when the account is first created. Internal processes in Windows refer to an account`s SID rather than the account's user or group name.

Service Pack

A software upgrade to an existing software distribution that contains updated files consisting of patches and hotfixes.

simple volume

A dynamic volume made up of disk space from a single dynamic disk. A simple volume can consist of a single region on a disk or multiple regions of the same disk that are linked together.


A type of tool that you can add to a console supported by Microsoft Management Console (MMC). A stand-alone snap-in can be added by itself; an extension snap-in can be added only to extend the function of another snap-in.

split Windows imaging file (.swm)

A collection of read-only files that contain one or more volume images of a Windows operating system, captured by using the ImageX tool.

striped volume

A dynamic volume that stores data that is allocated alternately and evenly (in stripes) across two or more physical disks.


See Other Term: attach

swap file

See Other Term: paging file

system context

The state of Windows after it first starts when some system services are loaded but no user is logged in and per-user settings are not available.

system control area

An area in the taskbar that shows icons for network connectivity, volume control, clock, and on laptops and Tablet computers, the battery.

system locale

Specifies the default language to use for non-Unicode programs. The system locale specifies the code page (ANSI, DOS, or Macintosh) that is used on the system by default. The system locale setting affects only ANSI applications (non-Unicode) applications. The language for non-Unicode programs is a per-system setting.

system partition

The partition that contains the hardware-specific files needed to load Windows. This is the partition that boots Windows.

System Restore

A tool that lets you restore your computer to a previous state, if a problem occurs, without losing your personal data files (such as Microsoft Word documents, browsing history, drawings, favorites, or e-mail). System Restore monitors changes to your computer and automatically creates restore points, so you can revert your computer to a previous state.

technician computer

The computer on which you install the Windows OEM Preinstallation Kit (Windows OPK) or the Windows Automated Installation Kit (Windows AIK), where you create answer files, build configuration sets, and build custom Windows images. The technician computer contains your distribution share.


See Other Term: Unified Extensible Firmware Interface


See Other Term: USB flash drive (UFD)

UI language

User-interface language. The language used to display the Windows user interface.


The Windows Setup answer file. Unattend.xml replaces answer files from earlier versions of Windows, including Unattend.txt, Winbom.ini, and others.

unattended Windows installation

The end-to-end process of automating the installation and the configuration of Windows. An unattended Windows installation includes tasks run in Windows PE, audit mode, and Windows Welcome, in addition to Windows Setup.

unattended Windows Setup

The process of running the Setup.exe command to install Windows. Unattended Windows Setup requires an answer file to configure Windows during installation.

unattended Windows Setup answer file

The answer file that automates Windows Setup, typically called Unattend.xml. This file enables the configuration of Windows settings, the addition and removal of components, and many Windows Setup tasks, such as disk configuration.


A character-encoding standard developed by the Unicode Consortium that represents almost all of the written languages of the world. The Unicode character repertoire has multiple representation forms, including UTF-8, UTF-16, and UTF-32. Most Windows interfaces use the UTF-16 form.

USB flash drive (UFD)

A removable, rewritable data storage device.

user account

In Active Directory, an object that consists of all the information that defines a domain user, which includes user name, password, and groups in which the user account has membership. User accounts can be stored in either Active Directory or on your local computer.

User Account Control (UAC)

Adds security to Windows by limiting administrator-level access to the computer. Limits the contexts in which a process executes and minimizes the ability of users to inadvertently expose their computer to viruses or other malware.

user context

The state of Windows after a user is logged on and the appropriate account permissions for that account are effective.

user locale

The setting that determines which formatting dates, times, currency, and large numbers are default settings for each user. Also determines the order for sorting text.

virtual hard disk

A file that can hold data equivalent to what is normally stored on a hard drive, including an entire operating system. A virtual hard disk (.vhd) can be run on a virtual machine hosted by the Hyper-V role in Windows Server or on designated hardware as the sole operating system on a computer.


A storage area on a hard disk that is formatted with a file system. Volumes have drive letters assigned to them. A single hard disk can have multiple volumes. Some volumes can span multiple hard disks.

volume image

A single Windows installation, along with any other applications, files, and settings, in a Windows image (.wim) file.


See Other Term: Windows Deployment Services

Windows Deployment Services

Software services that enable an administrator to set up new client computers remotely, without having to visit each client. The target clients must support remote booting. Windows Deployment Services is the replacement for Remote Installation Services (RIS).

Windows distribution

The collection of files released with Windows. This collection includes the Langpacks directory, the Sources directory, and other directories and files required for Windows Setup.

Windows image

An instance of the Windows operating system.

Windows image (.wim) file

A file format that can contain one or more compressed Windows images and other application and data files. Alternatively, a Windows image file can contain application and data files to be associated with one or more instances of Windows.

Windows Installer

An operating system service that enables the operating system to manage the installation process. Windows Installer technologies are divided into two parts that work in combination: a client-side installer service (Msiexec.exe) and a Windows Installer (.msi) file. Windows Installer uses the information contained within a package file to install the application.

Windows Logo Program

A certification program to help customers identify systems, hardware, and software that meet a baseline definition of platform features and quality goals and ensure a good user experience of Windows.

Windows Management Instrumentation (WMI)

A management infrastructure in Windows that supports monitoring and controlling system resources through a common set of interfaces and provides a logically organized, consistent model of Windows operation, configuration, and status.

Windows PE

See Other Term: Windows Preinstallation Environment (Windows PE)

Windows Preinstallation Environment (Windows PE)

A minimal Win32 installation environment with limited services. Built on the Windows kernel, Windows PE provides an environment to prepare a computer for Windows installation, copies disk images from a network file server, and starts Windows Setup.

Windows Setup

The program that installs or upgrades the Windows operating system.

Windows System Image Manager (Windows SIM)

A utility for creating and modifying unattended answer files and configuration sets.

Windows Update

The API platform, user interface, and Web service for delivering Windows updates and applications. Users can check for and install updates, view the update history for the computer, and turn on or change automatic updating settings. Windows Update can be used by consumers through the Windows Update Web service or by corporate customers who use Windows Server Update Services to control distribution within their organization.

Windows Welcome

The end user's first experience of Windows. Through a series of pages, Windows Welcome quickly and easily helps end users personalize their settings. Windows Welcome is formerly known as Out-Of-Box Experience (OOBE).


See Other Term: Windows Management Instrumentation (WMI)


The combination of a 64-bit Windows operating system and microprocessors that natively support x86 for extended systems (x64) 64-bit instruction set.


The combination of a 32-bit Windows operating system and a microprocessor that natively supports the 32-bit x86 instruction set.