Protect your Personal Computer (PC)

Antivirus Software - An Overview
We strongly recommend that you help protect your computer from viruses by installing and using an antivirus program. The Internet is full of fun places and vast amounts of information, but also some dangers. Your computer can be damaged by a computer virus sent through e-mail or through a program downloaded from the Web. If you do not use antivirus software, you run the risk of passing viruses along to other computers as well. If you administer a network without virus protection software, all of the computers on your network might be vulnerable.


Virus

A virus is a program that can copy itself and infect various parts of your computer, such as documents, programs, and parts of your operating system. Most viruses attach themselves to a file or part of your hard disk and then copy themselves to other places within the operating system. Some viruses contain code that inflicts extra damage by deleting files or lowering your security settings, inviting further attacks.


Worm

different from viruses in that they copy themselves from system toA worm is a program that makes copies of itself and can spread outside your operating system; it can copy itself from one computer to another by using e-mail or another transport mechanism. Worms can damage computer data and security in much the same ways as viruses, but are system.


Trojan Horse

A Trojan horse is a harmless-looking program designed to trick you into thinking it is something you want, but which performs harmful acts when it runs. It is typically received through downloads from the Internet. Trojan horses do not spread by themselves like viruses and worms. Most virus protection programs only detect a limited number of Trojan horses. A good way to help protect your computer from Trojan horses is to visit only Web sites you trust, and avoid downloading things unless you trust the source as well.


How do antivirus programs help protect your computer?
horses. If a virus, worm, or Trojan horse is found, the antivirus program either quarantines it or deletes it entirely before it damages yourAntivirus programs scan e-mail and other files on your computer for viruses, worms, and Trojan computer and files.

antivirus programs have an automatic update capability. When your antivirus software is updaSome companies that make antivirus programs provide regular updates for viruses. Manyted, new viruses are added to a list of viruses to check for, protecting your computer from new attacks. If your antivirus updates are not automatic, we recommend that you check for updates on viruses are identified every day. If a frequent basis because new the antivirus program you are using requires a subscription, we strongly recommended that you keep the subscription current to receive regular updates. If your list of viruses is out of date, your computer is vulnerable to new threats.

Where can I get an antivirus program?
There are many antivirus programs on the market.

Some of the companies which sell Antivirus softwares are listed above.

Computer Hard Disk Drive

Hard Disk
Hard disks were invented in the 1950s. They started as large disks up to 20 inches in diameter holding just a few megabytes. They were originally called "fixed disks" or "Winchesters" (a code name used for a popular IBM product). They later became known as "hard disks" to distinguish them from "floppy disks." Hard disks have a hard platter that holds the magnetic medium, as opposed to the flexible plastic film found in tapes and floppies.

At the simplest level, a hard disk is not that different from a cassette tape. Both hard disks and cassette tapes use the same magnetic recording techniques described in how tape recorders work. Hard disks and cassette tapes also share the major benefits of magnetic storage -- the magnetic medium can be easily erased and rewritten, and it will "remember" the magnetic flux patterns stored onto the medium for many years.


How it works

Nearly every desktop computer and server in use today contains one or more hard-disk drives. Every mainframe and supercomputers is normally connected to hundreds of them. You can even find VCR-type devices and camcorders that use hard disks instead of tape. These billions of hard disks do one thing well -- they store changing digital information in a relatively permanent form. They give computers the ability to remember things when the power goes out.

In this article, we'll take apart a hard disk so that you can see what's inside, and also discuss how they organize the gigabytes of information they hold in files!