File Management, Virus Protection, and Backup

1. Section A File Basics CHAPTER 4 File Management, Virus Protection, and Backup PARSONS/OJA Page 168

2. Chapter 4 File Management, Virus Protection, and Backup Chapter PREVIEW • 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 Page 169

3. Section A Chapter 4 File Basics Filenames, Extensions, and Formats: What are the rules for naming files? • Every file has a name, and might also have a filename extension • You must provide a valid filename that adheres to rules or file-naming conventions Page 170

4. Section A Chapter 4 File Basics What are the rules for naming a file? Page 170

5. Section A Chapter 4 File Basics Are filename extensions important? • Filename extension further describes the file contents • Separated by the filename with a dot • Readme.txt, Newsletter.doc • Related to the file format, the arrangement of data in a file, and the coding scheme used to represent the data • Most software programs have a native file format that is used to store files • They display any files that have the filename extension for its native file format Page 171

6. Section A Chapter 4 File Basics Are filename extensions important? Click to start Page 171

7. Section A Chapter 4 File Basics File Locations, Folders, and Paths: How do I designate a file’s location? • You first specify where 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 Page 172

8. Section A Chapter 4 File Basics What’s the purpose of folders? • An operating system maintains a list of files called a directory for each disk, CD-ROM or DVD • Folders - smaller lists within directories • A folder is separated from a drive letter and a filename by a backslash (\) Page 172

9. Section A Chapter 4 File Basics What’s the purpose of folders? • A file specification (path) is the drive letter, folder, filename, and extension that identifies a file C:\Music\Reggae\Marley One Love.mp3 drive letter extension filename Primary Folder Secondary Folder Page 172

10. Section A Chapter 4 File Basics File Sizes and Dates. Sorting… Page 173

11. Section A Chapter 4 File Basics 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 Page 173

12. Section B Chapter 4 File Management What’s the difference between the Save option and the Save As option? Renaming file…Saving with new name Page 175

13. Section B Chapter 4 File Management What other options does the Save As dialog box provide? • You can use it to rename a file, delete a file, or create a folder Click to start Page 175

14. Section B Chapter 4 File Management File Management Utilities: How does the operating system help me manage files? • File manager utility software • provided by your computer operating system • helps you locate, rename, move, copy and delete files Page 176

15. Section B Chapter 4 File Management Windows Explorer: How do I use a file management utility? • Windows Explorer is an example of a file management utility Click to start Page 178

16. Section B Chapter 4 File Management Is data stored in specific places on a disk? Page 180

17. Section B Chapter 4 File Management How does a disk get formatted? Malfunctioning floppy disks… • Formatting utilities are supplied by operating system or by companies that manufacture the drives Page 180-81

18. Section B Chapter 4 File Management How does the operating system keep track of a file’s location? Page 182

19. Section B Chapter 4 File Management 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 FAT. 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 • Helpful if you want to make sure that your personal data no longer remains on the hard disk • Individual bought 158 used hard drives on EBAY just to obtain personal info on them • Tax returns, 3,700 credit card numbers, bank account numbers, legal and medical records • Only 12 were properly purged • What happens when you put your computer in the trash??? • Europe requires recycling • 63 million PCs placed in U.S. landfills in 2003 Page 182

20. Section B Chapter 4 File Management How does the Recycle Bin affect file deletions? • Deleted files are moved to the Recycle Bin folder • Helps to protect against accidental erasures • Can you retrieve files from the Recycle Bin??? Page 183

21. Section B Chapter 4 File Management 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. Page 183

22. Section B Chapter 4 File Management How does a disk become fragmented? Page 183

23. Section C Chapter 4 Computer Viruses Viruses, Trojan Horses, and Worms: What’s the technical definition of a virus? • A computer virus is 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 Page 185

24. Section C Chapter 4 Computer Viruses What’s the technical definition of a virus? • File virus - a virus that attaches itself to an application program • Chernobyl - designed to lurk in computer until April 26 • A boot sector virus infects the system files that your computer uses every time you turn it on. • Computer lab…. • A 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 • File attachments Page 186

25. Section C Chapter 4 Computer Viruses How is a Trojan horse different from a virus? • A modern day Trojan horse is a computer program that 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 Page 186

26. Section C Chapter 4 Computer Viruses What’s a worm? • A software worm is a program designed to enter a computer system through security holes • usually through a network • does not need to be attached to a document to reproduce • 8/03: Blaster worm: attacks Air Canada’s reservation system • Denial of Service attacks Page 186-187

27. Section C Chapter 4 Computer Viruses How are viruses spread? Page 187

28. Section C Chapter 4 Computer Viruses How are viruses spread? • Viruses are spread through e-mails as well • 8/03: SoBig Virus • Placed virus on pc which sent e-mail to everyone in your address book with virus attached • Shut down CSX rail system • Macro viruses are usually found in MS Word and MS Excel files (.doc and .xls) • To keep safe, you can disable macros on files you do not trust Page 187-188

29. Section C Chapter 4 Computer Viruses What are the symptoms of a virus? • Your computer displays a vulgar, embarrassing or annoying message • Your computer develops unusual visual or sound effects • You have difficulty saving files: files mysteriously disappear • Your computer reboots suddenly • Your computer works very slowly • Your executable files unaccountably increase in size • Your computer starts sending out lots of e-mail messages on its own Page 188

30. Section C Chapter 4 Computer Viruses Too much Microsoft…. • 95% of operating system software designed by Microsoft • If hackers can find a flaw in this software they can utilize this to impact many computers, not just a few…. • If we used several different operating systems creating viruses would not be so much fun… • Recently a panel of “experts” called Microsoft’s dominance of the software market a national security concern Page 188

31. Section C Chapter 4 Computer Viruses Antivirus Software: What’s antivirus software? • Antivirus software is a set of utility programs that looks for and eradicates a wide spectrum of problems such as viruses, Trojan horses, and worms Page 189

32. Section C Chapter 4 Computer Viruses 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 Page 189

33. Section C Chapter 4 Computer Viruses How does antivirus software work? • Antivirus software also checks for a virus signature – a unique series of bytes used to identify a known virus Page 189

34. Section C Chapter 4 Computer Viruses When should I use antivirus software? • “All the time” • Does slow machine performance • Most antivirus software allows you to specify what to check and when to check it • Norton Antivirus • McAfee Antivirus Page 189

35. Section C Chapter 4 Computer Viruses How often should I get an update? • New viruses and variations of old viruses are unleashed just about everyday • Check website of antivirus software publisher for periodic updates • Software can be set to update itself automatically. This is what you want… • Must also keep your operating system up to date with patches prepared by Microsoft • And if you have a home network, you need a firewall Page 190

36. Section D Chapter 4 Data Backup Backup and Restore Procedures: How do I make a backup? • Data backup, a copy of a file or the contents of a disk drive, provide 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, your backup software, and your personal backup plan • Data rewind Page 193

37. Section D Chapter 4 Data Backup How do I restore data? • You restore data from a backup to the original storage medium or its replacement Page 194

38. Section D Chapter 4 Data Backup What’s the best backup plan? Page 194

39. Section D Chapter 4 Data Backup Do I have to back up every file? • Not necessarily, you could just back up most important files such as your data files • Best is to select a strategy • Store data files in specific location. Offsite! • Also backup: • Internet connection information • E-mail folders • E-mail address book • Favorite URLs • Downloads Page 194-195

40. Section D Chapter 4 Data Backup How often should I back up my data? • Backup your data depending upon how much data you can afford to use • Under normal use, once-a-week should be good enough Page 196

41. Section D Chapter 4 Data Backup How many sets of backups do I need? • One backup is good, but in case your backup gets corrupted, you should maintain a rotating set of backups Page 196

42. Section D Chapter 4 Data Backup Will all of my backups contain the same files? • 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 Page 196

43. Section D Chapter 4 Data Backup Will all of my backups contain the same files? • Incremental backup - copy of all files that have changed since the last backup • not necessarily since the last full backup, but since any previous backup • takes the least time but is most complex to restore • requires good recordkeeping • label correctly Page 196

44. Section D Chapter 4 Data Backup How can I make sure that my backups will work? • Test your backups periodically Page 197

45. Section D Chapter 4 Data Backup Do I need a boot disk? • A boot disk is 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 • Windows Startup Disk – it loads OS, and the CD-ROM drivers necessary for your computer to access files on the CD-ROM • Antivirus software creates rescue disk with boot info and antivirus software Page 197-98

46. Section D Chapter 4 Data Backup Can I store my backups on the Internet? • Several web sites offer fee-based backup storage space • When needed, you simply download backup files from the Web onto your hard disk • Definitely offsite storage • But what if they go out of business??? Page 198

47. Section D Chapter 4 Data Backup Do floppy disks and Zip disks play any role in backups? • Floppy disks are inexpensive, contain 1.44 MB space, and are good for several documents • Zip disk’s 100 MB and 250 MB capacity is sufficient for documents and digital graphics Page 198-199

48. Section D Chapter 4 Data Backup What about writable CDs and DVDs? • Writable optical technologies provide good storage capacity and blank disks are fairly inexpensive Page 199

49. Section D Chapter 4 Data Backup How about a second hard disk drive? • Good backup option • Disadvantage: susceptible to same dangers of first drive • Fire, theft, etc. Page 199

50. Section D Chapter 4 Data Backup How do I choose a backup device? What about flash drives??? 128 MB Page 199