Chapter 4: File Management, Virus Protection, and Backup Chapter 1: Computer, Internet, Web, and E-Mail Basics Chapter 4: File Management, Virus Protection, and Backup 1 1 1 1

Chapter 4 Preview After this chapter, you should be able to: Create valid names for files and folders Use file management features Describe how a computer physically stores files Explain viruses, boot sector viruses, macro viruses, Trojan horses, worms, and Denial of Service attacks Describe how antivirus software is used Understand backup and restore plans Compare backup devices Chapter 4: File Management, Virus Protection, and Backup

Chapter 4 Outline Section A Section B Section C Section D File Basics File Management Section C Computer Viruses Section D Data Backup Chapter 4: File Management, Virus Protection, and Backup

Chapter 4 File Management, Virus Protection, and Backup Section A: File Basics Computer Concepts 8th Edition Parsons/Oja

File names, Extensions, and Formats: What are the rules for naming files? Every file has a name, and might also have a file extension You must provide a valid file name that adheres to rules or file-naming conventions Chapter 4: File Management, Virus Protection, and Backup Page 176

What are the rules for naming a file? Chapter 4: File Management, Virus Protection, and Backup Page 176

Why are certain characters and words not allowed in a filename? Certain characters have significance to an operating system DOS and Windows use the “:” C: (representing hard drive), A: (representing floppy drive) Reserved words are words that are used as commands or special identifiers and cannot be used as file names Chapter 4: File Management, Virus Protection, and Backup Page 177

Are file extensions important? File extension further describes the file contents Separated by the file name with a dot Readme.txt, Newsletter.doc Related to the file format Most software programs have a native file format that is used to store files Chapter 4: File Management, Virus Protection, and Backup Page 177

Are file extensions important? Chapter 4: File Management, Virus Protection, and Backup Page 177

File Locations, Folders, and Paths: How do I designate a file’s location? You first specify where the file will be stored A: for floppy disk drive C: for hard drive D through Z for additional storage CD, Zip and DVD drive letters are not standardized Chapter 4: File Management, Virus Protection, and Backup Page 178

What’s the purpose of folders? An operating system maintains a list of files called a directory for each disk, CD-ROM or DVD Root directory Main directory of a disk Provides a useful list of files Folders - smaller lists within directories A folder is separated from a drive letter and a filename by a backslash (\) Chapter 4: File Management, Virus Protection, and Backup Page 178

File Sizes and Dates Chapter 4: File Management, Virus Protection, and Backup Page 179

What’s the significance of a file’s size? A file contains data, stored as a group of bits The more bits, the larger the file File size is usually measured in bytes, kilobytes, or megabytes Chapter 4: File Management, Virus Protection, and Backup Page 179

Is the file date important? Your computer keeps track of the date that a file was created or last modified The file date is useful if you have created several versions of a file and want to make sure that you know which version is the most recent Chapter 4: File Management, Virus Protection, and Backup Page 179

Chapter 4 File Management, Virus Protection, and Backup Section B: File Management Computer Concepts 8th Edition Parsons/Oja

Application-Based File Management: How does a software application help me manage files? Applications provide a way for opening and saving files from/to specific folders on a designated storage device An application may also provide additional file management capabilities Deleting and renaming files Chapter 4: File Management, Virus Protection, and Backup Page 180

What’s the difference between the Save option and the Save As option? Chapter 4: File Management, Virus Protection, and Backup Page 181

What other options are available in the Save As dialog box? You can use it to rename a file, delete a file, or create a folder Chapter 4: File Management, Virus Protection, and Backup Page 181

File Management Utilities: How does the operating system help me manage files? Provided by your computer operating system Helps you locate, rename, move, copy, delete files and discover file properties Chapter 4: File Management, Virus Protection, and Backup Page 182

These metaphors are also called logical storage models File Management Metaphors: How can a file management utility help me visualize my computer’s file storage? A storage metaphor helps you visualize and mentally organize the files on your disks and other storage devices These metaphors are also called logical storage models Chapter 4: File Management, Virus Protection, and Backup Page 183

What storage metaphors are typically used for personal computers? Storage metaphor is like a filing cabinet Another is the tree storage metaphor Chapter 4: File Management, Virus Protection, and Backup Page 183

Windows Explorer: How do I use a file management utility? Windows Explorer is an example of a file management utility Chapter 4: File Management, Virus Protection, and Backup Page 184

Can I work with more than one file or folder at a time? Select the files or folders Hold down Ctrl key, and click each item Click first, then hold Shift key and click on last item Select the operation to be carried out (rename, copy, delete, or move) Chapter 4: File Management, Virus Protection, and Backup Page 184

What can I do with the folders and files that are listed in Windows Explorer? Rename – change the name of a file or folder Copy – copy a file from your hard disk to a floppy disk Move – move a file from one folder to another Delete – delete a file when you no longer need it Chapter 4: File Management, Virus Protection, and Backup Page 184

File Management Tips Use descriptive names Maintain file extensions Group similar files Organize your folders from top down Consider using the My Document default directory Do not mix data files and program files Chapter 4: File Management, Virus Protection, and Backup Page 185

File Management Tips No files in the root directory Access files from the hard disk Follow copyright rules Delete files you no longer need Be aware of storage locations Back up Chapter 4: File Management, Virus Protection, and Backup Page 186

Physical File Storage: Is data stored in specific places on a disk? The physical storage model describes what actually happens on the disks and in the circuits A storage medium must be formatted Formatting creates the equivalent of electronic storage bins by dividing a disk into tracks, and then further dividing each track into sectors Chapter 4: File Management, Virus Protection, and Backup Page 186

Is data stored in specific places on a disk? Chapter 4: File Management, Virus Protection, and Backup Page 186

How does a disk get formatted? Formatting utilities are supplied by operating system or by companies that manufacture the drives Chapter 4: File Management, Virus Protection, and Backup Page 187

How does the operating system keep track of a file’s location? The OS uses a file system to keep track of the names and locations of files that reside on a storage medium Mac OS – Hierarchical File System (HFS) Linux – Ext2fs Windows NT, 2000, XP – NTFS Master File Table Windows 95, 98, ME - FAT32 Windows 3.1 - FAT16 Chapter 4: File Management, Virus Protection, and Backup Page 187

How does the operating system keep track of a file’s location? To speed up the process, sectors are grouped into clusters File allocation table (FAT) - an operating system file that maintains a list of files and their physical location on the disk Like a table of contents A damaged FAT results in losing data Chapter 4: File Management, Virus Protection, and Backup Page 187

How does the operating system keep track of a file’s location? Chapter 4: File Management, Virus Protection, and Backup Page 188

What happens when a file is deleted? The OS simply changes the status of the file’s clusters to “empty” and removes the filename from the index file It doesn’t remove the data, just the references to it Special file shredder software can be used to overwrite “empty” sectors with random 1s and 0s Chapter 4: File Management, Virus Protection, and Backup Page 188

Can deleted files be undeleted? Deleted files are moved to the Recycle Bin Helps to protect against accidental erasures Files that appear in the directory listing for the Recycle Bin folder can be undeleted Chapter 4: File Management, Virus Protection, and Backup Page 189

How does a disk become fragmented? As computer files are added/deleted, parts of files tend to become scattered all over the disk These fragmented files are stored in noncontiguous clusters Slows drive performance Defragmentation utility – rearranges the files on a disk so that they are stored in contiguous clusters Chapter 4: File Management, Virus Protection, and Backup Page 189

How does a disk become fragmented? Chapter 4: File Management, Virus Protection, and Backup Page 189

Chapter 4 File Management, Virus Protection, and Backup Section C: Computer Viruses Computer Concepts 8th Edition Parsons/Oja

Viruses, Trojan Horses, and Worms: What is a computer virus? A program that attaches itself to a file, reproduces itself, and spreads to other files A virus can perform a trigger event: Corrupt and/or destroy data Display an irritating message Key characteristic is their ability to “lurk” in a computer for days or months quietly replicating themselves Chapter 4: File Management, Virus Protection, and Backup Page 191

What is a computer virus? File virus - a virus that attaches itself to an application program Boot sector virus - infects the system files that your computer uses every time you turn it on Macro virus - infects a set of instructions called a “macro” Macro - a miniature program that usually contains legitimate instructions to automate document and worksheet production Chapter 4: File Management, Virus Protection, and Backup Page 192

How is a Trojan horse different from a virus? Appears to perform one function while actually doing something else Not a virus, but may carry a virus Does not replicate itself Another type of Trojan horse looks like a log-in screen PictureNote Trojan – arrives as e-mail named picture.exe and then tries to steal login and e-mail passwords Chapter 4: File Management, Virus Protection, and Backup Page 192

What’s a worm? A program designed to enter a computer system through security holes Usually through a network from computer to computer Does not need to be attached to a document to reproduce Mass-mailing worms Klez, Netsky, MyDoom, and Bagle Spoofed addresses Chapter 4: File Management, Virus Protection, and Backup Page 193

What are the symptoms of a malicious code attack? Network traffic jam Denial of Service Browser reconfiguration Delete and modify files Access confidential information Performance degradation Disable antivirus and firewall software Chapter 4: File Management, Virus Protection, and Backup Page 195

Antivirus Software: How can I avoid viruses and worms? Antivirus software is a set of utility programs that looks for and eradicates viruses, Trojan horses, and worms Chapter 4: File Management, Virus Protection, and Backup Page 196

How does antivirus software work? Hackers have created viruses that can insert themselves into unused portions of a program To counterattack the work of hackers, antivirus software designers created software with a checksum - a number calculated by combining binary values of all bytes in a file Compares checksum each time you run a program Chapter 4: File Management, Virus Protection, and Backup Page 196

How does antivirus software work? Checks for a virus signature A unique series of bytes used to identify a known virus Chapter 4: File Management, Virus Protection, and Backup Page 197

When should I use antivirus software? “All the time” Most antivirus software allows you to specify what to check and when to check it Chapter 4: File Management, Virus Protection, and Backup Page 197

How often should I get an update? New viruses and variations of old viruses are unleashed just about everyday Check Web site of antivirus software publisher for periodic updates Some software periodically reminds you to check for updates Chapter 4: File Management, Virus Protection, and Backup Page 197

How reliable is antivirus software? Antivirus software is pretty reliable, but viruses try to get around detection Multi-partite viruses Polymorphic viruses Stealth viruses Antivirus software is not 100% reliable, but protection is worth the risk Chapter 4: File Management, Virus Protection, and Backup Page 197

Virus Hoaxes: What’s a virus hoax? Some viruses don’t really exists A virus hoax arrives as an e-mail message containing dire warnings about a supposedly new virus that is on the loose Recommends a strategy Recommends forwarding the email Says no one has a fix for it yet Many cases it is a fake Chapter 4: File Management, Virus Protection, and Backup Page 197

What’s a virus hoax? Chapter 4: File Management, Virus Protection, and Backup Page 198

What should I do about virus hoaxes? Don’t panic You can ignore a virus hoax You can validate the hoax by going to a reliable Web site that lists hoaxes and viruses Chapter 4: File Management, Virus Protection, and Backup Page 198

Chapter 4 File Management, Virus Protection, and Backup Section D: Data Backup Computer Concepts 8th Edition Parsons/Oja

Backup and Restore Procedures: How do I make a backup? Data backup - a copy of a file or the contents of a disk drive Provides the best all-round security for your data A backup is usually stored on a different storage medium from the original files The exact steps that you follow depend on your backup equipment, the software you use to make backups, and your personal backup plan Chapter 4: File Management, Virus Protection, and Backup Page 199

How do I make a backup? Chapter 4: File Management, Virus Protection, and Backup Page 199 53

How do I restore data? You restore data by copying files from a backup to the original storage medium or its replacement Chapter 4: File Management, Virus Protection, and Backup Page 200

What’s the best backup plan? Chapter 4: File Management, Virus Protection, and Backup Page 200

What about backing up the Windows Registry? It is always open, so some backup software won’t back it up If possible, make a backup Update backup every time you install new software or hardware Chapter 4: File Management, Virus Protection, and Backup Page 201

How do I avoid backing up files that contain viruses? Use and update frequently antivirus software Scan and remove viruses before making backup Chapter 4: File Management, Virus Protection, and Backup Page 202

How often should I back up my data? Backup your data depending upon how much data you can afford to lose Under normal use, once-a-week should be good enough Chapter 4: File Management, Virus Protection, and Backup Page 202

Where should I store my backups? Store backups in a safe place Store backups in a different location Chapter 4: File Management, Virus Protection, and Backup Page 202

How do I choose a backup device? Chapter 4: File Management, Virus Protection, and Backup Page 202

What are the limitations of CDs and DVDs? Writing process is slow Restoring a crashed computer is cumbersome Writable optical technologies provide good storage capacity and blank disks are fairly inexpensive Chapter 4: File Management, Virus Protection, and Backup Page 203

Can I use floppy disks and Zip disks to back up my data? Floppy disks are inexpensive, contain 1.44 MB space, and are good for several documents Zip disks with 100 MB and 250 MB capacity is sufficient for documents and digital graphics Several 750 MB Zip disks might be sufficient for backing up all of your data files Chapter 4: File Management, Virus Protection, and Backup Page 203

Can I store backup files on a network server? If connected, you can store your files onto the network Get permission first Store your data in a password-protected, non-shared folder (remember networks are shared) Make sure the server is backed up on a regular basis Chapter 4: File Management, Virus Protection, and Backup Page 204

Can I back up to a second hard disk? Good backup option Disadvantage: susceptible to same dangers of first drive Chapter 4: File Management, Virus Protection, and Backup Page 204

What about using a tape drive for backups? Tape backup Used in business Data is copied to magnetic tape Tape drive can be internal or external Stored digital format Chapter 4: File Management, Virus Protection, and Backup Page 204

Where can I get backup software? Backup software is provided with many backup devices, particularly tape drives Microsoft Backup Useful features include Ability to restore all of your programs and data files without manually reinstalling Windows or any other applications An option to schedule unattended backups Support for a variety of backup devices Chapter 4: File Management, Virus Protection, and Backup Page 204

How do I use backup software? Full backup - copy of all files on a disk; safe but can take a long time Computer cannot be used during backup Backup device requires equal capacity Differential backup - copy of all files that have changed since the last full backup Takes less time but more complex Requires one full backup and then you will make differential backups at regular intervals Chapter 4: File Management, Virus Protection, and Backup Page 205

How do I use backup software? Incremental backup - copy of all files that have changed since the last backup Not necessary since the last full backup, but since any previous backup Takes the least time but is most complex to restore Requires good record keeping Label correctly Chapter 4: File Management, Virus Protection, and Backup Page 205

How do I use backup software? Chapter 4: File Management, Virus Protection, and Backup Page 205

What is a boot disk? A floppy disk or CD that contains the OS files needed to boot your computer without using hard drive Most manufacturers include a recovery CD for restoring your system to original setup The Windows XP Backup utility creates a set of Automated System Recovery disks Chapter 4: File Management, Virus Protection, and Backup Page 206

What is a boot disk? Chapter 4: File Management, Virus Protection, and Backup Page 206

Conclusion You should now be able to: Create valid names for files and folders Use file management features Describe how a computer physically stores files Explain viruses, boot sector viruses, macro viruses, Trojan horses, worms, and Denial of Service attacks Describe how antivirus software is used Understand backup and restore plans Compare backup devices Chapter 4: File Management, Virus Protection, and Backup