Managing A Personal Computer Essay, Research Paper

1.1 The AUTOEXEC.BAT file is one of files

which loads every time the computer is booted. It contains command lines

and procedures to run programs and load settings for the system?s hardware

and software configuration. It also may contain command lines procedures

to run programs which may clean your system?s hard drive of temporary files

and viruses.

An example of this file is shown below:

@ECHO OFF

PROMPT $P$G

SET PATH=C:\DOS

LH C:\SBCD\DRV\MSCDEX.EXE /S /D:MSCD001

/M:8 /V

SET BLASTER=A220 I5 D1 T4

SET SOUND=C:\SBPRO

C:\MOUSE\MMOUSE.COM

The first line of this batch file, @ECHO

OFF, is programming command which hides all the command lines procedures

from the user.

The second line is also a programming

command that configures the CUI command prompt. The parameters after PROMPT

tell the CUI what to show. The $P stands for current drive and path and

$G stands for the greater than sign (>). Apart from those two parameters,

a user can add any characters after PROMPT and it?ll be shown as the command

prompt.

The next command configures the CUI to

search for files in that directory first before looking in its current

location. The SET and PATH command procedures, even though different commands,

are used in conjunction to configure CUI environment variables and the

parameters displayed after that are what the CUI will search in first.

The next command is loading DOS?s CD-Rom

drive letter allocater (The CD-Rom driver must be loaded first in the CONFIG.SYS).

The parameters after the executable file inform the CUI to allocate a particular

drive letter for the CD-Rom and also may inform the CUI to allocate extended

memory or how to read the CD-Rom in terms of speed and sectors. The LH

configures the CUI to load this command procedure in high or extended memory.

The next command procedure allocates the

Interrupt and Drive Memory allocation for the system?s sound card as well

as informing the CUI of the sound card?s input/output range.

The next command procedure informs the

CUI to look for all the drivers for the sound card in its parameters which

will be a directory on the hard disk.

The last command loads the driver for

the mouse. This command procedure doesn?t need any parameters and is just

a single command procedure telling the CUI to load that executable file.

1.2 A Batch File Which Asks For User Input:

@echo off

cls

IF “%1″==”C” GOTO DRIVE

IF “%1″==”D” GOTO DRIVE

if “%1″==”c” goto drive

if “%1″==”d” goto drive

echo Please type INSTALL X (Replace X with

your hard drive letter)

echo eg. INSTALL C

goto :quitinstall

RIVE

echo Welcome to the Batch Input Demo written

by Leon Douglas.

echo.

echo Do You wish to continue?

choice /n Yes or No

cls

echo off

md %1:\minstall

cd %1:\minstall

echo off

copy a:\inst2.bat

inst2

:quitinstall

Without going into excessive detail of

this batch program, what it is accomplishing is a drive letter to install

a program into as well as a yes or no instruction to continue. The first

part of the batch file which is in bold is the piece of programming that

requires a drive letter to be typed as a parameter to the batch file. It

will only recognise C or D as drive letters, whether it be as uppercase

or lowercase. If the user does not type a parameter or types a different

drive letter other than C or D, the batch file will display a message that

states a drive letter is required before continuing.

In the second piece of programming which

is in italics is what the user will see if they type C or D as a parameter

next to the batch file?s name as the command procedure. This part of the

programming asks the user whether to continue with the installation or

not. If the user types anything apart from yes,no,y or n the program will

not proceed until the correct parameter is typed. If the user enters the

correct parameter the program will proceed to the next step which is shown

above in bold and Italics. This part of the batch program makes a directory

on the given drive and then copies another batch file from the same location

as itself to the directory it created. From here, this batch file terminates

after the command procedure is given to start the other batch file.

1.3 Macros That Automate Procedures Within

A GUI (Windows)

Within Windows 95 there are several ways

that procedures can be automatically loaded without the input of a user.

The two most common methods are by placing command line procedures as icons

within the Startup folder of Windows or by placing the command line procedures

in the LOAD= line of the WIN.INI. Another method is by placing the command

line procedure within the Windows Registry but that is the most complex

method.

To automate procedures via the Startup

folder is a very easy task. Simply make a new icon or shortcut within the

folder and browse for the executable file you would like to load. Simply

save the icon and next time windows is loaded, that executable will be

loaded at the start up as well.

To add command line procedures into the

WIN.INI file is just as easy, here is an example:

[windows]

spooler=yes

load=c:\scenes\scenes.exe navpopup.exe

There are two executables as you can see,

navpopup.exe and scenes.exe, and these are loaded at the startup as well.

The space between the two is all that is needed for Windows to differentiate

between the two programs but parameters can also be placed in as well.

As you can also see, navpopup.exe doesn?t have a directory path so the

file must be within the SET PATH command line procedure in the AUTOEXEC.BAT.

1.4 To produce single keystroke operations

for various tasks, also known as Hot Keys, is very simple. For an example,

within Windows 95, a hot key can be assigned to open a particular executable.

This is done by opening the properties of the executable icon and adding

a letter in the Shortcut Key box.

2.1 Installing or Upgrading a software

package within a CUI is a very easy task. An example would be to install

a game that doesn?t have any sub-directories. The game will be on a floppy

disk and we will have to make a directory on the hard disk. It would go

as follows:

C: {Enter}

MD GAME {Enter}

CD GAME {Enter}

COPY A:\ {Enter}

The game no can be played by simply typing

the executable file name under the directory ?GAME?

.

2.2 To install or upgrade a software package

within a GUI is usually very simple as the package will have its own SETUP.EXE

file which will do it all for you. But, for the sake of it we?ll do an

example that doesn?t contain a SETUP.EXE file. The installation example

is as follows:-

1. Open Windows Explorer

2. Click on A: and select all the file

on the disk by clicking on the first file, hold shift down, and by pressing

the down arrow key until it reaches the last file.

3. While all the files are selected, right

mouse click on any of those files and click on COPY.

4. Click on the C: and make a directory

by clicking on the Root directory of where you want to install it and click

on NEW FOLDER from the File Menu.

5. Type in the name of the new folder

and press enter

6. Right mouse click on that folder and

click on paste. It is now copied onto the Hard Disk.

To make a shortcut on the desktop simply

right mouse click anywhere on the desktop and then click on NEW SHORTCUT.

Browse for the executable file of the software package and select it. Done.

2.3 To adjust the GUI to accept the new

software would probably only arise when manually installing a software

package where an older version of the same package exists on the CUI. If

this is the case, then there are a couple of steps to be taken. The first

step would be to check the lower half of the WIN.INI file for any configuration

settings for the old, existing version of the software package. An example

is below:

[WinZip]

win32_version=6.3

Name=LeonD

SN=sdf08s789s

As you can see, the configuration within

the WIN.INI tells Windows that the Version is 6.3 so that would have to

be changed to coincide with the new installation. The serial number will

usually be the same, but if not, change that here as well. Usually as a

word of wisdom, always try to UPGRADE software if you have an existing

version because installing a new version can cause problems if an existing

version is also on the GUI.

Also, if you do INSTALL a newer version,

always remove the old version before you install the newer by going to

ADD/REMOVE within CONTROL PANEL. This will delete all the old configuration

settings for the older version.

2.4 Conflicts will only arise in software

when the above situations (2.3) do arise. As a word of wisdom, always try

to UPGRADE over existing software, never INSTALL newer versions onto a

system that contains the older versions. If you have to, always delete

the old version via the Control Panel (Add/Remove) to remove any risk of

conflicting software.

3.1 The Major Types Of Viruses:-

Boot Sector Viruses ? Attempts to replace

or inflect the boot sector of a hard or floppy disk.

File Infectors ? Attempts to infect executable

file and spreads virus when infected executable files are run. Multiparite

Virus ? Attempts to infect both executable files and boot sectors.

Polymorphic Virus ? Mutates each time

it replicates to stay one step ahead of anti-virus software.

Stealth Virus ? Attempts to falsify checksum

values to evade detection.

Systemic Virus ? Targets the FAT partition

tables, device drivers and the system files (IO.SYS & COMMAND.COM)

3.2 The method of virus prevention is to

try to eliminate all the possible sources of how viruses can infect your

system. One way is to never run anything of floppy disks, CD-Roms or the

Internet and the other is to simply install Anti-Virus software. Just remember

that a virus cannot just appear, it has to be copied onto your system or

run off a floppy disk from your system. In today?s society, viruses are

being written every day and computers are infected every day, but most

makers of viruses only want to infect and damage information of rather

large companies such as banks or law enforcement agencies. The only way

you will get infected is by opening documents on your system that came

from external sources and most of the top anti-virus packages will scan

these documents and software packages before your system even opens them

so there is a way to deal with viruses. The way an anti-virus package does

this is by sitting resident in the background of a GUI or CUI and scans

each document which is opened. For example, if you place a floppy disk

in your computer and open it using Windows Explorer, the anti-virus package

will automatically scan the disk for you and instantly disinfect or inform

you of any viruses.

3.3 Installing anti-virus software is the

easiest part. The hardest part is finding the right package for you which

will perform all the tasks you need it to. When I look for an anti-virus

package, it MUST be able to do a surface scan of my computer each day apon

booting in the CUI by loading the AUTOEXEC.BAT. The other crucial task

it should be able to do is sit resident in the background of my GUI, scanning

everything I open and automatically disinfects or informs me of any virus

it finds.