Speaking. Discuss the following questions.
1. What is a computer virus?
2. How do viruses spread?
3. Are there different kinds of viruses?
4. What is a Trojan horse? What is a bot?
5. What is a botnet?
6. How can you avoid viruses and worms?
7. What is antivirus software? How does it work?
Text D
Reading. Read the text and try to guess the meaning of the words in bold. Check your variants in the dictionary.
Data Backup
Backup and restore procedures
Have you ever mistakenly copied an old version of a document over a new version? Has your computer's hard disk drive gone on the fritz? Did a virus wipe out your files? Has lightning “fried” your computer system? These kinds of data disasters are not rare; they happen to everyone. You can’t always prevent them, so you need a backup plan that helps you recover data that's been wiped out by operator error, viruses, or hardware failures.
A backup is a copy of one or more files that has been made in case the original files become damaged. A backup is usually stored on a different storage medium from the original files. For example, you can back up files from your hard disk to a different hard disk, a writable CD or DVD: tape, floppy disk, or Web site.
A good backup plan allows you to restore your computing environment to its pre-disaster state with a minimum of fuss. Unfortunately, no single backup plan fits everyone’s computing style or budget. You must devise your own backup plan that’s tailored to your particular computing needs.
A full-system backup contains a copy of every program, data, and system file on a computer. The advantage of a full-system backup is that you can easily restore your computer to its pre-disaster state simply by copying the backup files to a new hard disk. A full-system backup takes a lot of time, however, and automating the process requires a large-capacity tape backup device or a second hard disk drive.
A workable alternative to a full system backup is a “selective” backup that contains only your most important data files. The disadvantage of this backup strategy is that because you backed up only data files, you must manually reinstall all your software before restoring your data files.
If your strategy is to back up your important data files, the procedure can be simplified if you’ve stored all these files in one folder or its subfolders.
In addition to data files you create, a few other types of data files might be important to you. Consider making backups of these-files:
- Internet connection information
- E-mail folders
- E-mail address book
- Favorite URLs
- Downloads
Windows users often hear a variety of rumors about backing up the Windows Registry. The Registry, as it is usually called, is an important group of files the Windows operating system uses to store configuration information about all the devices and software installed on a computer system.
As simple as it sounds, backing up the Registry can present a bit of a problem because the Registry is always open while your computer is on. Windows users whose backup plans encompass all files on the hard disk must make sure their backup software provides an option for including the Windows Registry.
Your backup schedule depends on how much data you can afford to lose. If you’re working on an important project, you might want to back up the project files several times a day. Under normal use, however, most people schedule a once-a-week backup. If you work with a To Do list, use it to remind yourself when it is time to make a backup.
Store your backups in a safe place. Don’t keep them at your computer desk because a fire or flood that damages your computer could also wipe out your backups. Storing your backups at a different location is the best idea, but at least store them in a room apart from your computer.
Backup devices
The backup device you select depends on the value of your data, your current equipment, and your budget. Most computer owners use what they have — a writable CD drive, Zip drive, or floppy disk drive.
The major disadvantage of backing up your data on CDs and DVDs is that the writing process is slow — slower than writing data to tape or a removable hard disk. Further, although it is feasible to back up your entire system on a series of CDs or DVDs, you would have to use special backup software, monitor the backup process, and switch disks occasionally. CDs and DVDs are more practical for backing up a select group of important data files.
Zip disks with 100 MB or 250 MB capacity are sufficient for backups of documents and most digital graphics files. Several 750 MB Zip disks might be enough for backing up all your data files and could be feasible for a full-system backup if you have not installed lots of application software.
A second hard disk drive is a good backup option — especially if it has equivalent capacity to your main hard disk. This capacity allows the backup process to proceed unattended because you won’t have to swap disks or CDs. Speed-wise, a hard disk is faster than tape, CD, or DVD drives. Unfortunately, like your computer’s main hard disk, a backup hard disk is susceptible to head crashes, making it one of the least reliable storage options.
Network and internet backup
If your computer is connected to a local area network, you might be able to use the network server as a backup device. Before entrusting your data to a server, check with the network administrator to make sure you are allowed to store a large amount of data on the server. Because you might not want strangers to access your data, you should store it in a password-protected, non-shared folder. You also should make sure the server will be backed up on a regular basis so that your backup data won’t be wiped out by a server crash.
Several Web sites offer fee-based backup storage space. When needed, you can simply download backup files from the Web site to your hard disk. These sites are practical for backups of your data files, but space limitations and download times make them impractical for a full-system backup. Experts suggest that you should not rely on a Web site as your only method of backup. If a site goes out of business or is the target of a Denial of Service attack, your backup data might not be accessible.
Backup software
To make a backup, you can use backup software — a set of utility programs designed to back up and restore files. Backup software usually includes options that make it easy to schedule periodic backups, define a set of files that you want to regularly back up, and automate the restoration process.
Backup software differs from most copy routines because it typically compresses all the files for a backup and places them in one large file. Under the direction of backup software, this file can spread across multiple tapes if necessary. The file is indexed so that individual files can be located, uncompressed, and restored.
Boot disks
A boot disk is a floppy disk or CD containing the operating system files needed to boot your computer without accessing the hard disk. A barebones boot disk simply loads the operating system kernel. It is needed, if your hard disk fails or a virus wipes out the boot sector files on your hard disk, you will not be able to use your normal boot procedure.
To create an MS-DOS boot disk, insert a blank floppy disk in drive A. Open My Computer or Windows Explorer, and then right-click the Drive A icon. Select Format and check the box labeled Create an MS-DOS startup disk.
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