File Organization and Protection

1. File Organization and Protection Topic 5

2. Content • Files • Hard Drives • Viruses • Optimize Computer System

3. Files • A file in a computer system is a sequence of bits stored as a single unit • Files are stored on a optical disk, magnetic disk, or electronic storage (Flash drive)

4. Files • My system • Hard drive is partitioned into 6 sections • Three sections are in Linux; not seen by Windows • Two sections are C: and D: • One section is boot drive (very small) • Windows remember things by putting small files here when computer boots • DVD-Read/Write Drive • Removable Drive, Flash Drive • Windows 7 – color codes • Red means drive has less than 10% of free space

5. Files

6. Files • Flash drive, hard drive, DVD – CD ROM drives • Tree-like file structure • Similar to a filing cabinet • Navigate through the levels of your file structure • Make folders to store files logically • Windows normally installed on C drive • Linux operating system • Bootable from DVD or CD • Bootable from a flash drive

7. Files

8. Files • Note – my drive is complicated • Windows folder – Windows operating system • Program folder – Where software programs are stored • Note – I have two because I have a 64-bit processor and 64-bit Windows 7 • Program folder (x86) means 32-bit programs • Program folder means 64-bit programs • User folder - stores user data like desktop, My documents, etc.

9. Hard Drives • Important drive for storage and retrieval of large amount of data • Data is stored sequentially on magnetic disks • Disk is called a platter • A read/write head passes over the disk on an arm • Hard drives have different speeds • 5,400 rotations per minute(RPMs) • 7,200 RPMs • Faster speed allows data to be stored or retrieved faster • Note – new hard drives are solid state • Similar to a flash drive • No mechanical moving parts • More expensive with smaller capacities

10. Hard Drives

11. Hard Drives • Files should be stored sequentially on drive • Fragmentation - Usually Windows put file pieces in different spots • File segments are not in sequence • Takes longer to retrieve files, especially if drive is over 10% fragmented • Hard drive works harder • Slows system down, especially for laptops • CPU waits longer for stored or retrieved data

12. Hard Drives • Windows has a disk defragmenter • Usually slow; completely reorganizes drive • No pretty pictures • I used Auslogics Disk Defrag • Free disk defrag utility • Gives picture of drive • Organizes files very quickly

13. Hard Drives

14. Hard Drives

15. Hard Drives • Hard drives can fail • Usually after three or more years • Hard drive is dropped to the floor • Hard drive makes squeaky noises before it fails • Data should be backed up • External hard drives are cheap • Online storage • Store files at a website; retrievable from anywhere in the world as long as you have an internet connection • Examples • Flipdrive • Supersync • Elephant drive

16. Hard Drives • Windows and Linux • When you delete files, the operating system leaves the data there • It only changes the file allocation table • A table keeps track where the pieces of a file are located • A deletion tells the computer that new places are free for new data and files • These files are easily recovered • Other time, large files like music and movies will be destroyed as new files are written over them • Small files like documents, emails, and pictures can survive for awhile • If you edited a Word document 20 times, those 20 copies may still be on the drive

17. Hard Drives • If you have sensitive data on your drive, never throw your computer or hard drive away. • Remove the drive and keep it • Physically destroy the hard drive • Use a special program to format the drive • Changes all information to ones or zeros • Quick format does not change the information • It only changes the file allocation table • Special programs exist that recover data • Recuva – a free and excellent program

18. Hard Drives • File compression • Some files are large • Use compression to reduce file size • Not so important for hard drives • Hard drives have large capacities and are cheap • Important for email • Limited in attachments for emails • Common programs • Built in Windows XP, Vista, and 7 • Winzip • 7-zip

19. Hard Drives • Windows (and Linux) fill the drive with junk • Temporary programs • Installation files • Internet files and history • Pictures, websites, and content • Restore files • Over time, this junk can take up giga bytes of hard drive space away • Periodically clean this • CCleaner – free cleaner

20. Hard Drives

21. Hard Drives • Registry Cleaner – a program that cleans a computer’s registry • Registry – unique to Windows • A hierarchical database for the Windows Operating System • Configuration settings • Software options • Tracks the performance of the operating system • Do not manually edit the registry! • Do not manually edit the registry!

22. Hard Drives • If the registry is damaged or corrupted, Windows may not work • Either replace registry with a backup • Or re-install your Windows Operating System • To change or edit registry is type regedit on command line • Instructor: • Uses a registry cleaner to remove unwanted entries • Improves speed for a laptop • Some do not recommend this! • I used Eusing

23. Hard Drives

24. Viruses Virus Infected Computer • Virus – malicious code • Create annoyances, like dancing icons on desktop • Destroy system files and information • Transmission • Infected media like flash drive, etc. • Email attachment • Install unknown program from internet • Visiting malicious websites

25. Viruses • Other problems from malicious code • Worms – malicious code that replicates itself through a network or internet • Worms take advantage of security flaws in a computer • User does not have to do anything • Origin of spam emails, etc. • Rootkit – dangerous type of virus • Root is the main system directory in Unix (or Linux) • Rootkit means a virus has penetrated the system files and has authority to change any system setting • Malware – steal passwords, credit card information, etc. • Very difficult to detect and eliminate

26. Viruses • Spyware – program tries to collect information • Keylogger – program that reads characters typed on a keyboard • Passwords, etc. • Malware • Usually does not try to propagate itself • Not like a virus or worm • Usually user is tricked to download or installing a program

27. Viruses • Adware – advertising programs keep popping up in new windows • Once a computer is infected, a virus or worm may open a door for more viruses and worms • One virus grows into ten or more very quickly

28. Viruses • How do you know your are infected? • Computer is slower • Very long boot time • Files mysterious disappears • Webpages keep opening up • Advertising to remove viruses, worms, etc. • This company may have put it there • Programs act strangely or crash frequently • Anti-virus program is disabled • Worse case – destroys the operating sytem

29. Viruses • Virus Protection • Antivirus Programs • Program scans memory, Windows registry, and file system for viruses • Takes up resources, especially for a laptop • Scans emails for threats • Usually do not scan for Spyware or Rootkits • Usually more programs for these

30. Viruses • Antivirus Programs • Bitdefender 1 • Kaspersky 2 • Webroot 3 • Norton 4 • ESET Nod32 5 • AVG Antivirus 6

31. Viruses • Antivirus programs are not free • Computer files need to be continually scanned • Antivirus needs to be continually updated • Creators continually create new viruses • Ignoring updates can jeopardize system • Antivirus is normally a subscription • You pay for a license per year • Usually one license for one computer • Prices range from $30 to $100

32. Viruses • KasperskyAntivirus • Some say it is the best • It made my system sluggish • AVG Antivirus • Has a free version • Does not hog up system resources • Very basic protection

33. Viruses Firewall Firewall for a Network • Firewall – a program (or hardware) that monitors data flow between a computer and a network or internet • Firewall blocks unauthorized programs • Comes with Windows Operating System

34. Viruses • Windows Firewall • Go to Control Panel • Firewall is its own option • Antivirus programs may also provide a firewall • Usually an upgrade • Usually adds to the cost

35. Viruses

36. Viruses • Antivirus is only partial protections • Rootkitscanners; some are free • Sophos Anti-Rootkit • GMER • RootRepeal • Dr Web Cure it

37. Viruses • Spyware and Malware (not rootkits) • Spybot (free program) • www.safer-networking.org • Immunization – protects internet explorer and Firefox from bad websites • Tea timer – prevents changes to msconfig.exe • MSConfig is system configuration • Type msconfig in command window • Tells which programs to load when system is booted • Popular place for viruses

38. Viruses • Windows Defender • Free spyware program for Windows • Requires Genuine Windows • Another way for Microsoft to check if operating system has a proper license • Type winver in command window for this information

39. Optimize Operating System • Review • Use a cleaner to remove temporary files • Use registry cleaner (potentially dangerous) • Use disk defrag to defragment a hard drive • Important for laptops • Use msconfig to prevent certain programs from loading • Periodically run antivirus, rootkit scanners, and spyware scanners • Keep Windows and Programs updated • Patches security problems • Usually takes space and makes programs slower