FILE ORGANIZATION AND PROTECTIONTopic 5

CONTENT Files Hard Drives Viruses Optimize Computer System

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)

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

FILES

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

FILES

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.

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

HARD DRIVES

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

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

HARD DRIVES

HARD DRIVES

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

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

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

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

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

HARD DRIVES

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!

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

HARD DRIVES

VIRUSES

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

Virus Infected Computer

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

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

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

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

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

VIRUSES Antivirus Programs

Bitdefender 1 Kaspersky 2 Webroot 3 Norton 4 ESET Nod32 5 AVG Antivirus 6

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

VIRUSES Kaspersky Antivirus

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

VIRUSES

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

Firewall Firewall for a Network

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

VIRUSES

VIRUSES Antivirus is only partial protections Rootkit scanners; some are free

Sophos Anti-Rootkit GMER RootRepeal Dr Web Cure it

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

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

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