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What are hardware and software?


            Physical devices such as monitor, floppy disk drive, hard disk, keyboard, printer(s) are called hardware. Hardware does all operations in your PC such as accepting and storing data, calculations and display or printing.


            Hardware cannot work on their own. To make it work a set of programs will be required. A set of programs associated with the operation is called software. Software can be of different types


  1. Operating System e.g. DOS, Windows etc.
  2. Programming language such as BASIC, FORTRAN, C++, etc.
  3. Application programs/packages such as word processors, spreadsheet, database management system (DBMS) etc.
  4. Others application programs e.g. accounting, payrolls, billing, ticket reservation etc.


Firmware refers to the small software programs that are stored in read only memory (ROM) of the computer. They are used to start the computer and perform low-level input/output instructions to control input/output devices.


What is Operating System?


            The operating system is a collection of programs that control all hardware and other resources in the computer system. It is the operating system that operates and controls the CPU, memory, various I/O devices such as keyboard, mouse, video display unit, printer etc. For instance when you press a key on the keyboard it is the operating system that accepts the key and provides it to the word processor.


            Besides controlling and managing the computers resources, operating system also does following job


1.      File Management: The operating system creates and manages the directory system on the secondary storage devices. And also commands to copy rename and delete files and directories on secondary storage devices.

2.      It contains a text editor that can be used to create simple text files.

3.      It is the operating system that implements job priority when running multiple programs simultaneously.

4.      It maintains an internal real time clock known as system clock. This clock is used to mark the date and time of creation or modification of files. This is known as time stamping of files. This is known as time stamping of files.

5.      It acts as an interface between the user and the computer.

6.      It has utility programs to help the user to control the behavior of the computer system.



Popular operating system for PCs


            Following are most popular operating system for PCs


1.      DOS and Windows 3.1

2.      Windows 98

3.      Windows 2000

4.      Windows NT

5.      UNIX and LINUX


Windows 3.1 is not an operating system. It is a program that runs on DOS to create an operating environment.

Disk Operating System (DOS) was the first operating system developed for IBM PC by Microsoft Corporation. This was called DOS because all program files required to start this operating system were stored on a floppy disk.

Compared to DOS based PC, windows operating system can

1.      display characters in different shapes and also display graphics.

2.      run more than one program simultaneously.


Disk operating System


            On loading DOS, the screen displays C:\>,C>,A:\> etc. called the system prompt. It indicates the default drive name and that DOS is ready to accept command from keyboard.


Changing Default Drive


            Type the new drive name with : and press enter. If you enter a drive letter that does not exists then DOS shows a message.


Not ready reading drive A

Abort, Retry, Fail?


What is a File?


            A file is a collection of text or data stored on a storage device. Usually, one computer file stores one kind of information. The file that stores letter, documents, etc. is called document or text file. The file that stores databases information, such as address list or sales information is called database file. A file that contains instructions is called a program file.


            Each file is given a name called filename.  Filename in DOS can be of eight characters, it can have a period (.) followed by extension name of three characters.




The extension name helps in identifying a file e.g. DOC for document file and COM for command file. While naming, we can use following characters

A-Z, a-z, 0-9, !, @, #, $, %, ^, &, -, _,{ }, ‘, ~,()


What is a directory?


            A directory is a named section of storage device such as hard disk, floppy disk or compact disk. It helps to organize files in an efficient manner. You can store any number of files in each directory.

            Like a filename, directory name can also have up to eight characters and can have an extension up to three characters.


Displaying list of files with DIR


            This Command lists files and sub-directories in a disk’s directory. Besides filename, it displays file size (in bytes) and date and time of creation/last update. It also displays number of files listed, total bytes occupied and free space available on the disk.




To get list from some other drive, specify the drive name followed by ‘:’ with DIR. e.g. C:>DIR B:


To get a summary of the directory listing, use /W after DIR.

If the directory listing is too long to fit on screen, use /P with DIR to get page wise listing.

If we use command DIR *.DOC it will list all ‘.DOC’ files. The character ‘*’ is called wildcard character.

Another wildcard character -?.



This command will list filenames, such as SALE1REP, SALESREP, SALE_REP.bak, etc.






Changing the Directory


            To change the directory, use the CHDIR or CD command, e.g.


            CHDIR \EXCEL

            CD \EXCEL

            CD C:\EXCEL

            CD C:\EXCEL\SALES

            If the EXCEL directory exists in default drive, DOS will select it. Otherwise, it will display the message –“Invalid directory”.


Creating a New Directory


            The command to create a new directory is MKDIR or MD. To create a new directory


1.      Select the drive where you wish to create a new directory.

2.      If you wish to create the new directory at root level, select the root directory with the command CD\ or CHDIR\.

3.      Use the MKDIR or MD command.


If you wish to make a directory BOOKS under the WORD directory in drive C, then


·        If the prompt is not showing ‘C:>’, type C: to select drive C.

·        Type CD \WORD to change the current directory to C:\WORD.

·        Type MKDIR BOOKS or MD BOOKS


Copying Files


To copy files from one storage device to another use the COPY command


            COPY source destination

Source is the path and the filename(s) of the files(s) to be copied. Destination is the path where the files are to be copied.

e.g.       C:>COPY C:REPORT A:

            C:>COPY A:CHAPTER1.DOC C:

            C:>COPY A:CHAPTER1.DOC C:\WORD


To give a new name to the copied file.



To copy several files wildcards can be used.

e.g.       C:>COPY C:*.DOC A:

            C:>COPY C:SALE?REP A:


e.g.       C:>COPY REPORT A:

            C:\WORD>COPY DATA1.DOC A:

            C:>COPY D:\SAMPLE.TXT A:\

            C:\WORD>COPY C:\EXCEL\EMP01.XLS C:\


Deleting Files with DEL/ERASE


The DEL or ERASE is used to remove a file.

e.g.       C:>DEL A:\SAMPLE.TXT

            C:>DEL A:\WORD\*.TXT

            C:>DEL \WORD\*.DOC

            C:>ERASE C:TEXT.DOC

            C:\WORD>DEL *.*



Changing Filename with RENAME (REN)


            Use the RENAME or REN to change the filename of existing file(s).


                        C:>RENAME SAMPLE.TXT NEW.DOC

                        C:>REN SAMPLE.TXT NEW.DOC

                        A:>RENAME C:\WORD\SAMPLE.DOC NEW.DOC




            DOS maintains a real time calendar clock. To see or change the current date, the DATE command can be used.



            Current date and time is Thur 25-08-05

            Enter new date(dd-mm-yy):


To see or change the current time, the TIME command can be used.



            Current time is 3:48:20p

            Enter new time:


Internal And External Dos Commands


            Internal commands are automatically loaded in the memory of your PC when DOS is loaded and can be used without any DOS file or diskette. The internal commands are used for copping, renaming or erasing files, displaying a list of files in a diskette, creating or changing directories, etc. the external commands are used for copying an entire disk, formatting a disk, comparing or joining files, sorting text, etc.






Formatting a disk with FORMAT


            FORMAT is an external DOS command and using it

·        It detects any bad area and marks that area as bad. DOS will not use that area for storing files.

·        Initializes the disk to accept DOS files and create the root directory.


To format a disk in drive A

·        Enter FORMAT A:

·        Now insert disk to be formatted in drive A and press enter.


Copying files with XCOPY


            XCOPY is used to copy files


            COPY A:*.* C:\

            XCOPY a:\*.* C:\


            For copying many files XCOPY is faster. The options that you can use with XCOPY are

·        Copy directories and lower level sub-directories.


·        Verify each file as it is copied.


·        Confirm before copying files.


·        Copies files modified on or after a specified date.

XCOPY A:*.EXE C: /D:05-07-05


Typing the file contents with TYPE


            The type command is used to display the contents of only text files on the monitor. You cannot use the TYPE command to display contents that contains non-printable characters.



            TYPE SAMPLE.TXT


Using MORE to display a long file


            The MORE can be used to display the contents of a file on the screen page by page.




            This command displays the first page on the screen. pauses, and displays the message “- - More - -“. It displays the next page on pressing a key on the keyboard.


Redirecting Output and Input


            DOS allows to redirect the output of a command to another command or file. The ‘>’ character is used to redirect or route the output of a command to another command or file.


            to redirect the output of DIR in file sample


To have the input of a command come from another file. e.g. to sort a list of names in NAMES.TXT






Moving Files with MOVE


            The MOVE command is used to move files from one directory to another or to rename directories.


            C:>MOVE A:\OLD\*.DOC A:\NEW

Moves all files with extension DOC.


Overwrite A:\SAMPLE.DOC (Yes/No/All)?




            Can be used to search for a text string in a text file.




tries to locate “Buffers” in the C:\CONFIG.SYS file, and displays all lines that contain this word. By default, the FIND command is case sensitive. To make the FIND command case insensitive, use ‘/I’ option:


            FIND /I “Buffers” C:\CONFIG.SYS


Using Batch Files


            A batch file contains a series of DOS commands having the extension ‘BAT’. It helps in running DOS commands without requiring your attention. You can type any DOS command in a batch file. Then ask DOS to run that batch file. DOS automatically executes all commands entered in the batch file, one command at a time.

Creating and running a batch file


            Let us create a simple batch file that will execute the following commands:



            DIR /P

We will create a batch file TEST.BAT.

·        If the prompt is not showing ‘C:>’, type C: to select drive C.


·        Enter COPY CON TEST.BAT.

·        Enter the following commands. Remember to press the Enter key at the end of each line.



                  DIR /P

·        To close the TEST.BAT file, press ^Z and press Enter.

·        Enter TEST or TEST.BAT to execute the TEST.BAT batch file.




ECHO Insert a disk in drive A



REM Insert a disk in drive A




My Computer

The My Computer icon is on the desktop and is used to find the resources of your PC.

·        Double click the My Computer icon and your PC displays the My Computer window. The My Computer window displays all drives, such as floppy, hard disk, CD-ROM, etc in your PC. It also includes Control Panel, Printers, Dial-Up Networking, etc.

·        Click the icon for hard disk. Windows displays the capacity of the hard disk and the used and available space on the drive.

·        Double click mouse on the icon for drive C, and windows displays a new window containing all files and folders at the root level.

·        For using menu through keyboard each menu label includes an underline letter, ‘F’ for file and ‘E’ for edit. Use these underline letters with the Alt key to open the corresponding menu, e.g. Alt F displays file menu. if you want to use next menu(edit), press right arrow key(à), similarly to see previous menu press left arrow(ß). If any menu is open press Esc twice to close it.

·        Look at edit menu. ‘Ctrl+A’ is shown against the select all command. These keys are called shortcut keys and are assigned to respective command.


Windows Explorer

            Windows Explorer enables you to see the folder and files in your computer in a hierarchical structure and also help to create, delete, copy or move contents of one folder to another.


Start à Programs à Windows Explorer


            Windows Explorer window has two panes. The left pane of the window displays all drives and folders. The right pane displays the contents of the selected drive or folder. If you want to see the contents of any drive or folder, click the desired drive/folder in the left pane.

            Windows Explorer displays ‘+’ or ‘-’ sign to left of folder or drive letter. The ‘-’ sign indicates that windows explorer is displaying all subfolders of the selected drive/folder. The ‘+’ sign indicates that there are some folders under the selected drive/folder that are not displayed at the moment. To see subfolders click mouse on ‘+’ and to hide the subfolders click on ‘-’.


Formatting a Disk

1.      Put the disk to be formatted in drive A.

2.      Right click mouse on ‘31/2 Floppy (A:)’ in left pane.

3.      Choose the format command from the menu.

4.      Choose the format options from the format window and then click on start button.

In the same way you can format a hard disk.



Creating a New Folder

            To create a new folder at the root level in drive C.

·        Click drive C: in the left pane of the windows explorer.

·        Right click the mouse in any empty area in the right pane. Alternatively, open the file menu.

·        Select the ‘New’ command from the menu.

·        Choose ‘Folder’ from the submenu.

·        Type a new name for the folder and press enter.


Renaming a file or folder

            Right click the mouse on the file or folder, choose the rename command, type the new name and press enter. Alternatively select the file or folder to be renamed then use the Rename command from the file menu.


Selecting Files

            To select multiple adjacent files

You can change the file selection by shift clicking any other file.


Sometimes you may like to select files from different parts of the directory. For selecting non-adjacent files


Copying files Using the Mouse

            To copy multiple files first you need to select the required files, then


The table shows the procedure to copy and move files to the same and different drives.



From one folder to another folder in the Same Drive

From one folder to another folder in a different Drive

Copy Files

Ctrl + drag files to the icon for destination folder or the destination folder window

Drag files to the icon for destination folder or the destination folder window with or without Ctrl key

Move Files

Drag files to the icon for destination folder or the destination folder window with or without Shift key pressed

Drag files to the icon for destination folder or the destination folder window with the Shift key pressed


Copying and Moving files Using the Keyboard

            To copy files using keyboard


To move files using keyboard


Deleting Files

To delete selected files press the Del key. Alternatively, right-click the mouse on the selected files and then choose the delete command.


Using Recycle Bin to Restore Items

            The Recycle Bin holds the items you delete, you can restore (i.e. undelete) all the items back to their original locations by clicking Restore All. If you want to restore selected items, select the required items and then choose the Restore command from the file menu or from the right-click menu.


Plug and Play

Plug and Play is a hardware specification that helps you to add and remove hardware devices, such as hard disc, floppy disc, mouse, scanner, etc. If the device you are trying to install is Plug and Play compatible, you should not have any problem in installing it. To install a device

1.      Shut Down Widows.

2.      Connect the device to your computer.

3.      Turn on your computer and start windows. Windows will automatically detect the new Plug and Play device and install the necessary software.

Adding/Removing Programs

            The first page of the Window (Install/Uninstall) is used to install a new program. To install a new program, click the install button and Windows will guide you through the installation process. The list of programs that Windows can automatically remove is shown in the lower half of the Install/Uninstall page. To remove a program, select that program and click the Add/Remove button.

            The second page enables you to Add/Remove a component of the Windows operating system.

            The Create Disc button on the Startup Disc page of the Add/Remove Program Properties windows can be used to create a Windows startup disk.