1. Gateway: device sitting at a network node for interfacing with passwords or assisting in product activation. In graphical
another network that uses different protocols. Works on OSI layers environments, installers that offer a wizard-based interface are
4 to 7. common. Attended installers may ask users to help mitigate the
errors. For instance, if the disk in which the computer program is
Router: a specialized network device that determines the next be installed was full, the installer may ask the user to specify
network point to which it can forward a data packet towards the another target path.
destination of the packet. Unlike a gateway, it cannot interface
different protocols. Works on OSI layer 3. Silent installation
Switch: a device that allocates traffic from one network segment to Installation that does not display messages or windows during its
certain lines (intended destination(s)) which connect the segment progress. "Silent installation" is not the same as "unattended
to another network segment. So unlike a hub a switch splits the installation" (see below): All silent installations are unattended but
network traffic and sends it to different destinations rather than to not all unattended installations are silent. The reason behind a
all systems on the network. Works on OSI layer 2. silent installation may be convenience or subterfuge. Malware is
always installed silently.
Bridge: a device that connects multiple network segments along
the data link layer. Works on OSI layer 2. Unattended installation
Hub: connects multiple Ethernet segments together making them Installation that is performed without user interaction during its
act as a single segment. When using a hub, every attached device progress or with no user present at all. An unattended installation
shares the same broadcast domain and the same collision domain. either does not require the user to supply anything or has received
Therefore, only one computer connected to the hub is able to all necessary input prior to the start of installation. Such input may
transmit at a time. Depending on the network topology, the hub be in the form of command line switches or an answer file, a file
provides a basic level 1 OSI model connection among the network that contains all the necessary parameters. Windows XP is an
objects (workstations, servers, etc.). It provides bandwidth which is example of an operating system that can be installed with an
shared among all the objects, compared to switches, which provide answer file. In unattended installation, it is assumed that there is no
a connection between individual nodes. Works on OSI layer 1. user to help mitigate errors. For instance, if the installation medium
was faulty, the installer should fail the installation, as there is no
Repeater: device to amplify or regenerate digital signals received user to fix the fault or replace the medium. Unattended installers
while sending them from one part of a network into another.
may record errors in a computer log for later review.
Works on OSI layer 1.
Headless installation
Installation performed without using a computer monitor
Some hybrid network devices:
connected. In attended forms of headless installation, another
machine connects to the target machine (for instance, via a local
Multilayer switch: a switch which, in addition to switching on OSI area network) and takes over the display output. Since a headless
layer 2, provides functionality at higher protocol layers. installation does not need a user at the location of the target
computer, unattended headless installers may be used to install a
Protocol converter: a hardware device that converts between two computer software on multiple machines at the same time.
different types of transmissions, such as asynchronous and
synchronous transmissions. Scheduled or automated installation
Bridge router (brouter): a device that combines router and bridge An installation process that runs on a preset time or when a
functionality and therefore works on OSI layers 2 and 3. predefined condition transpires, as opposed to an installation
process that starts explicitly on a user's command. For instance, a
system administrator willing to install a later version of a computer
Hardware or software components that typically sit on the connection point of program that is being used can schedule that installation to occur
different networks, e.g. between an internal network and an external network: when that program is not running. An operating system may
automatically install a device driver for a device that the user
connects. (See plug and play.) Malware may also be installed
Proxy server: computer network service which allows clients to automatically. For example, the infamous Conficker was installed
make indirect network connections to other network services when the user plugged an infected device to his computer.
Firewall: a piece of hardware or software put on the network to Clean installation
prevent some communications forbidden by the network policy
A clean installation is one that is done in the absence of any
Network address translator (NAT): network service provide as interfering elements such as old versions of the computer program
hardware or software that converts internal to external network being installed or leftovers from a previous installation. In
addresses and vice versa particular, the clean installation of an operating system is an
installation in which the target disk partition is erased before
Other hardware for establishing networks or dial-up connections: installation. Since the interfering elements are absent, a clean
installation may succeed where an unclean installation may fail or
may take significantly longer.
Multiplexer: device that combines several electrical signals into a Network installation
single signal
An installation of a program from a shared network resource. This
Network interface controller a piece of computer hardware to may simply be a copy of the original media but software publishers
allow the attached computer to communicate by network which offer site licenses for institutional customers may provide a
Wireless network interface controller a piece of computer version intended for installation over a network.
hardware to allow the attached computer to communicate by LAN
Modem: device that modulates an analog "carrier" signal (such as Some computer programs can be executed by simply copying them into a
sound), to encode digital information, and that also demodulates folder stored on a computer and executing them. Other programs are supplied
such a carrier signal to decode the transmitted information, as a in a form unsuitable for immediate execution and therefore need an
computer communicating with another computer over the installation procedure. Once installed, the program can be executed again and
telephone network again, without the need to reinstall before each execution.
ISDN terminal adapter (TA): a specialized gateway for ISDN
Line driver: a device to increase transmission distance by Common operations performed during software installations include:
amplifying the signal. Base-band networks only.
Attended installation
Making sure that required system requirements are present
This is the most common form of installation. An installation
process usually needs a user who attends it to make choices, such Checking for existing versions of the software
as accepting or declining an end-user license agreement (EULA), Creating or updating program files and folders
specifying preferences such as the installation location, supplying

2. Adding configuration data such as configuration files, Windows
registry entries or environment variables
Making the software accessible to user, for instance by creating
links, shortcuts or bookmarks
Configuring components that run automatically, such as daemons
or Windows services
Performing product activation