Managing A Personal Computer
Managing A
Personal Computer
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:SBCDDRVMSCDEX.EXE /S /D:MSCD001
/M:8 /V
SET BLASTER=A220 I5 D1 T4
SET SOUND=C:SBPRO
C:MOUSEMMOUSE.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
:DRIVE
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:scenesscenes.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.
