Operating system functions
Operating
System is
a software program that acts as an interface between the user and the computer.
It is a software package which allows the computer to function.
To act as interface between hardware and
users, an operating system must be able perform the following functions:
1. Enabling startup application programs.
Thus, the operating system must have:
- A text editor , A translator , An editor of
links
2. The allocation of resources needed to
execute programs is done by identifying: the programs that are running, the
need for memory, peripheral devices and data protection requirements.
3. Facilities for data compression, sorting,
mixing, cataloging and maintenance of libraries, through utility programs
available.
4. Plan implementation works according to
certain criteria, for efficient use of central processing unit.
5. Assisting implementation of programs
through computer-user communication system, at both hardware and software
level.
And
also others Functions:
Program creation ,
Program execution , Access to
Input/output devices , Controlled access to files , System access , Error
detection and response , Interpreting the commands , Managing peripherals ,
Memory management , Processor management
, Information management , Process communication , Networking
Basics components of
Windows
The main components of Windows when you start
your computer are the Desktop, My Computer, Recycle Bin, Start Button, Taskbar,
and shortcuts to applications.
After opening an application, you will also
have a window with an active application which will appear in your desktop and
taskbar.
Desktop:-
The image of a desktop was invented to make computers easier to use. The more
you compare this desktop with the situation behind a real desk, the faster you
will understand it.
Each
desktop may look slightly different and show different objects (icons and
buttons). Look on your screen and see if you can find the three icons on the
right. Each object on screen represents a Function. You get access to these
functions by touching them with the mouse and cursor.
Recycle Bin:-
Here we introduce the most important objects of the desktop. The 'Recycle Bin'
is a special folder. Like a real waste basket, you can use it to dispose of
things you no longer need. You can put
Documents
in it and take them out again, until you empty it.
My Computer:
- This icon symbolizes your computer. You use it to get access to documents or
programs on a Floppy-disk or a CD.'My Computer' also gives access to the 'hard
disk': the place within
the computer
where the programs and documents are kept.
S t a r t - b u t t o n :- The 'Start'-button gives you access to different
functions, like starting programs and shutting down the computer. When a
document is lost, you can use the Start-button to help you find it.
Taskbar:
- The Start-button is part of the 'Taskbar'. For each program you start, a
button is added to the Taskbar. This means you can open and use more programs
at the same time. When you want to
Switch
between programs you only click on its button in the Taskbar.
Cursor:
- The white arrow is the 'cursor'. You
use it to tell the computer what to do. You can move it on the screen by moving
the mouse with your hand. Try to move it to all four sides of your screen.
F o l d e r :- The yellow
icon is a 'Folder'. Like a real folder or cabinet, you can use it to store
things on the computer. You create your own folder(s) for your documents
Computer icon
A computer icon is a pictogram displayed on a computer screen and
used to navigate a computer system or mobile device. The icon itself is a small picture or symbol serving as a quick, intuitive
representation of a software tool, function or a data file accessible on the
system. It functions as an electronic hyperlink or file shortcut to access the program or data.
Computer icons, in conjunction with computer windows, menus and a pointing device, form the graphical
user interface (GUI)
of the computer system, and enable the user to easily and intuitively navigate
the system.
Using Desktops
A desktop allows you to organize applications
on up to four virtual desktops. Read email on one, browse the web on the
second, and do work in your productivity software on the third, without the
clutter of the windows you're not using. After you configure hotkeys for
switching desktops, you can create and switch desktops either by clicking on
the tray icon to open a desktop preview and switching window, or by using the
hotkeys.
Unlike other virtual desktop utilities that
implement their desktops by showing the windows that are active on a desktop
and hiding the rest, Desktops uses a Windows desktop object for each desktop.
Application windows are bound to a desktop object when they are created, so
Windows maintains the connection between windows and desktops and knows which
ones to show when you switch a desktop.
Activating windows
When installing a retail copy of Windows or Office, the user
is asked to input a unique product key supplied on a certificate of authenticity included with the program, which is later verified
during activation. Immediate activation is not required following installation,
but the program must be activated within a specific period of time in order to
continue to function properly. Throughout this grace period, the user will be
periodically reminded to activate the program, with warnings becoming more
frequent over time.
Activation is
performed with a utility supplied with Windows and Office called the Activation
Wizard. It can be performed either over the Internet or by telephone. When activating over the Internet,
the Activation Wizard automatically transmits and receives verification data to
and from Microsoft servers, completing the process without any interaction by
the user. Activation by telephone requires that a user and a Microsoft agent
verbally exchange activation information. In this case, an installation ID is
generated, which is then be read to the agent. The agent verifies the
information and replies with a confirmation ID, which is then typed into the
Activation Wizard
