Thursday 30 October 2008

Virus protection and Firewalls how and why they are used

Virus protection – a virus is a program or a piece of code loaded into your computer without you knowing. All computer viruses are manmade. A simple virus will make copies of the file over and over again. A simple virus is dangerous too it will use all available memory on your computer. The virus will destroy your computer, when there is a virus on your computer your computer will be slow. The virus that is more dangerous will spread from one network to another.

Trojan horse and worm are similar to viruses. Trojan horse disguises itself as another program, the programs are hidden an cause an unwanted effect. Trojan horse is different to viruses it s not designed to replicate like a virus. The software will be doing something normal, but actually the programs contains an attack program. Worm is a computer program which replicates itself. It spreads from one network to another. Worm is designed to destroy your computer, it causes damages to the host computer or attacking a third party computer. Worms are similar to viruses. The difference between virus and worm is that virus is a stand alone program which doesn’t hide in another program.

To stop the viruses from damaging your computer you should install an anti virus in your computer. The anti virus will protect you from viruses and when the is a virus the anti virus will destroy the virus. The software will need to be updated, when its updated the new version would be better it will have more features. If the software isn’t updated the software will detect the old viruses but it wont detect the new viruses.

Firewalls – firewall is a hardware and software which prevents communications prohibited by the security policy in a computer network. Firewall is used to give a users a secure access to the internet. Using a firewall is a good way of protecting personal information from being exposed to others. The firewall stops private and confidential information from being exposed to others and it stops viruses from entering the computer system.

A firewall protects our computers by putting up a barrier to keep anyone from accessing our files when we are surfing the on Internet. It protects networked computers from deliberate hostile invasion that could result in data corruption or denial of service and exposure of confidential data stored on the system.

Software versions are cheaper then the hardware type. It is installed into your computer to protect your computer from internet hazards. The three common internet hazards are:
• Remote login – allows someone to connect to your computer and control it
• Back doors – programs and operating systems have features that allow for remote access
• SMTP – takes over your mail list and sends out spam using your computer

Wednesday 29 October 2008

Function of the system unit components and how they communicate

The system component is the input devices, output devices, memory unit and central processing unit. The input devices enable data to be supplied to the computer. The output devices enable output of data from computer. The memory unit stores the data and the programs which the computer uses each time. The central processing unit is made of two parts the control unit and the arithmetic logic unit.

The input devices are:
• Keyboard – allows user to input data
• Mouse – pointing device which allows user to select icons or files
• Joystick - device used for video games and for some graphics applications
• Scanner - A device that takes a picture of an image, breaks it down into dots and records it as a digital file for use with a computer
• Microphone - An audio device that converts sound energy (such as voice waves) into electrical energy which can then be amplified

The output devices are:
• Display screen – VDU (visual display unit) – it allows you to see the data that you have entered on the screen
• Printer: laser printer, ink-jet printer – it allows you to print out a paper copy of the data on your computer
• Plotter - A plotter draws images as a series of point-to-point lines

Central processing unit (CPU)
• Control unit - that directs sequence of operations, interprets coded instructions, and initiates proper commands
• Arithmetic Logic unit - performs all arithmetic computations, such as addition and multiplication, and all comparison operations

How to Install and configure a DVD rewrite drive

This is a hardware installation it requires you to open the base unit. Once you have disconnected the power from the computer and opened the case, then first the power and IDE connector cables are to be removed from the CD ROM drive. The CD Drive will then be taken out either by a lever or if it is screwed onto the case depending on what type on case it is. Once removed and replaced with the DVD Re writer Drive then reconnect cables previously removed from CD Drive and close the case when that's done. Now reconnect the power and boot up the computer.



The above image shows the DVD rewrite in the my computer section, As you can see there is a CD RW in the drive which data has been written to the disc to test the newly installed DVD Re writer drive. There is a great advantage of having a DVD rewrite this is because DVD are used media disc format for movies and games which you can now play using the new DVD drive installed.

The effect and benefit on your computer system when you under take activities

There are many activities are undertaken to make the computer system better, faster and too cause less problems. Virus protection is used to stop viruses from destroying your documents; virus software will block all viruses. Viruses don’t need permission from users to destroy the files. The virus can go from one computer to another. By updating the virus definition files your computer becomes safe and virus free. The advantages of updating your definition files are that:
· Fully automated. It is only necessary to update one server to update all machines in the network.
· Minimal configuration required.
· Only the portion of the file that contains new data is retrieved by the computer. In previous versions, this was a feature that only Live Update had.

Scheduling your full system scan is a good thing because then you won’t forget to scan your computer for viruses. You can schedule the time when it’s right for you and when you’re not using the computer. The full system scan will be happening in the background. It will take time to scan your computer but it all depends on the number of files you have on your computer. The advantage of scheduling you’re your computer for a full system scan is that you will never forget to scan your computer and you will get a scan done every week when it’s scheduled for a scan.
Windows XP Service Pack 2 (SP2) is a fast, free way to improve protection of your organization’s Windows XP–based computers. Service Pack 2 provides advanced security technologies and innovations from Microsoft and establishes a stronger security infrastructure that helps defend against viruses, hackers, and worms. Service Pack 2 also includes tools that enable manageability and control so that it is easier to be safe and improves overall productivity by helping users avoid time-wasting threats.

Defragmentation is the process of locating the noncontiguous fragments of data into which a computer file may be divided as it is stored on a hard disk, and rearranging the fragments and restoring them into fewer fragments or into the whole file. Defragmentation reduces data access time and allows storage to be used more efficiently. Some operating systems automatically defragment storage once in a while; others require that the user occasionally uses a utility for this purpose.The advantage of defragmenting the hard drive is that:
· it allows you to select files and directories
· if you defragment your hard drive regularly it will increase the overall performance of your system
· Instead of defragmenting the whole disk you can select profiles to defragment
· User-friendly interface doesn't require a specific knowledge (look at screenshots)
· Possibility to move files to the end of the disk (for rarely used files)
· Defragmentation scheduler allows to set date and time for every profile

The advantages for drive formatting are that it allows compressing files and therefore saving space on your drive. File system lets you to add allow and deny permissions on individual files and folders for specific Windows users, something you cannot do in the FAT file system. When you are formatting your drive there is a chance of you loosing all your files so don’t forget to back up all your files in a removable disk.

Firewall is needed to protect outsiders from using your network. They can be using your network without you knowing. Unauthorized people can get in to your computer and start controlling your computer and sending out spam using your computer. Firewall is a system that secures your network. Firewall can be installed via hardware or software. The advantage of you having a firewall installed into your computer is that unauthorized users can’t get into your network and start using it.

When you create folders for your files all your documents are all organised and easy to find. You should create different folders for different documents, having the files in different folders saves time searching for the file if your files are in the right folder then you will find the file quickly. It saves time. Your folder doesn’t need to be in my documents folder it could be anywhere. There any many advantages for creating folders:
· Makes things easier for having a folder for each subject
· Saves time
· Files will be organised

You copy and paste from one place to another so it is in the right location. You would do this so it’s easy to find and you won’t have to spend too much time in finding the file. You can copy the files from your area on the computer to a USB or other storage devices. The advantage of this will be that the files are in the right place and if you save it on a USB there will be a back up copy of the document.

The advantage of deleting files is that all the files that you don’t need anymore you can delete, if the file is private and confidential and you don’t need it anymore you can delete the file and then empty the recycle bin. This way no one will see or find the document you have deleted. Having documents on your computer that you won’t need anymore takes up space on your computer. Having too many programs and files on your computer makes your slow and when you’re trying to save your file and there isn’t any space you won’t be able to save your documents.
The advantage of back up to CD using compression software is that

Backup compression used during the backup process can often reduce the mount of space required by 50% or more. You can easily backup your files with zip compression as to a single file as to multiple files. By using compression, you can backup to CD more than 1 GB.