Configuring A Computer - 1.18 - 1.20

1.18 COMPUTERS MAINTENANCE :

                  i)Both software and hardware must be considered.

                 ii)Maintenance contract can be taken out either with the hardware supplies or with an independent third party.

               iii)Hard ware maintenance comprises preventive maintenance cover.

               iv)Software maintenance comprises correction enhancements and updates.

1.18.1 Typical cause of system failure

1.      Component Failure : i)Thermal stress(hot and cold adverse) can  break the bond from the pad on the chip  causing an input/ output error.

                                ii)Remedy is replacing  the chip.

2.      HEAT: i)Destroy the chips inside the computer.

           ii)Remedy is installing an adequate fan or auxiliary fan in the power supply

      3.Dust an other particles :i)Causes thermal insulation due to dust in internal components.

                                             ii)Blocks the spaces such as  the air intake area to the power supply or hard disk.

                                       iii)Remedy is blowing the dust off with a can of compressed air.

3.      Noise interference: i)Electrostatic discharge form the human body and improper connections are  noise creators.

                      ii) Remedy is antistatic spray on rugs, carpets and computer equipment .

                     iii)Installing an antistatic floor mat beneath the computer chair.

4.      Power line problems: i)Causes by overvoltage or under voltage.

                                      ii)Remedy is Backup power supply(UPS)

5.      Magnetic fields: i)Voltages   monitors and television receivers produce strong magnetic fields.                                                                                                                     ii)Remedy is keeping the diskettes, tapes and even the information cables away form power sources and magnets.

6.      Corrosion: i)Causes by metal connector pins or cables, interface  cards, and chip pins.

                 ii)  Rub the pins clean to prevent corrosion.

1.18.2 Computer periodic check up

1.      Update the virus definitions                        2.Perform a full virus scan

               3.Reboot when programs crash                       4.Do a complete back up

               5.Run a spyware and adware removal program 6) Update the programs

               7)Check for new drivers                                 8)Clean out pc case

1.19 computer viruses

                  Symptoms of a computer virus

                The Computer,

1.      Runs slower than usual.

2.      Stops responding.

3.      Disks or disk drives are inaccessible

4.      Display unusual errors messages

5.      Display distorted menus and dialog boxes.

1.19.3     Definition:

i)A computer program that is designed to replicate itself by copying itself into the other programs stored in an computer.(OR) a destructive program.

ii)Causes the program to operate incorrectly or corrupting computer’s memory.

1.19.4 Types of viruses

                  1.  File viruses : Affect Executable  files

2.      Boot viruses:  Affect Boot sector or files.

3.      Macro viruses: Affect MS-office files. (spreadsheets and database)

4.      Network Virus: Spreads through emails

Example for virus.  :    Bomb, worm, and Trojan horse

1.20 COMPUTER SECURITY: Computer security refers to protecting computer systems and the information they contain against unwanted access, damage, modification or destruction.

                  1. Physical access restrictions: i)Access to authorized people.

                                                              ii)Access can be granted through identity card, user name and                  password, voice print, retinal scans, fingerprints and so on.

                                                              iii)Many systems use a combination of more than one control.

2. Password: A code by which a user gains access to a computer system.

                  3.Firewall: i)A software that usually runs on a proxy server of an organization

                                      ii)Controls the flow  of incoming and outgoing messages.

                  4.Backup :Duplicate set of program or data files in case the originals become damaged.