File Management, Virus Protection, and Backup Chapter 4.
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Transcript of File Management, Virus Protection, and Backup Chapter 4.
File Management, Virus Protection, and Backup
Chapter 4
Rules for Naming Files
When naming files, you must adhere to a set of rules called file-naming conventions
In newer versions of Windows, your filename must: Not exceed 255 character Contain */:<>|”\?
Filenames in newer versions of Windows can contains spaces and numbers and are not case sensitive
Reserved Words
There are certain words that the operating system might reserve only for its use in naming files.
In newer versions of Windows, these reserved words include:aux, com1, com2, com3, com4,
con, lpt1, lpt2,lpt3, prn, nul
File formats The file extension is related to the file
format, which tells the computer how the data is arranged and what was used to encode it.
Many software programs have a native file format which is the preffered type of file it likes to deal with. For example, the native format for MS Word is the DOC format and thus the .doc file extension
Saving Files on the Computer
The first choice you make is the physical location of the file such as the floppy disk (A:) the hard drive (C:) or some other location such as a CD burner.
After that, you may choose to place your file in a folder.
Folders are the graphical representations of the computers list of files called a directory
The main level in the directory is called the root director (generally the physical location)
C:\My Music\Reggae\MarleyOnelove.mp3
C:\ is the drive letter or root directory of the hard drive
My Music is the primary folder Reggae is a secondary folder Marleyonelove is the filename .mp3 is the file extension showing this as
a type of music file
This represents the file specification more commonly known as the path to the file
File Sizes and Dates
File manager also shows the size in KB of files on your computer
Also shows the date modified These can be useful for identifying the
latest version of something or determining if a file will fit on another media such as a floppy disk.
Dates can also be used in the search function to locate files.
File management in application software
From the save dialog box, you have a drop down menu that allows you to select a location for the new file
The file name and file type allow you to assign a name and file format.
From this menu you can also change the display options, create new folders, and navigate to different folders.
Should I “Save” or “Save As…”
First time a file is created, both options will do the same thing: allow you to select a filename and location
On files that have been saved previously, the Save option will save the file in the same location with the same name.
On files previously saved, Save As… allows you to change the location and name if you wish
Good to use Save As if you are making a second copy of a file to a floppy disk or other media
File Management Utilities
Windows provides “My Computer” and “Explorer”
My Computer shows the files and folders available in with icons or a list of filenames
Explorer shows files in a tree like hierarchy showing where files are while showing the entire file structure at the same time
More management information
In Explorer and My Computer, you can select more than one file by holding the CTRL key and clicking on the files you want to select
If all of the files are in a row, you can click the first item in the list and then hold the SHIFT key down to select the last item in the list
From here you can rename, copy, Move and delete files and folders
Some tips…
Use descriptive names so you’ll recognize your file from a list
Keep original file extensions so your computer knows how to open the file
Put related files in a folder together Maintain a good hierarchy of related
files
More tips
Use the My Documents folder for your files and add subfolders as needed
Don’t mix data and program files Don’t keep files in the root directory Copy files from disks to the hard
drive so they run faster
Even more tips…
Follow copyright Delete files no longer in use Monitor location of stored files Monitor storage space on devices to
make sure they aren’t getting close to full
Back up important data frequently
Physical File Storage
Formatting creates tracks on a disk and then divides them into sectors
Tracks and sectors are numbered to allow for addressing of each storage compartment
CDs and DVDs have spiraling tracks from the center and magnetic disks generally have concentric circles
Formatting a Disk
Generally accomplished through a file utility
For floppy disks, right click on the A: icon in my computer and choose Format Disk Fast format erases the disk Format erases the disk and recomposes the
sectors and tracks CD and DVD usually have a utility that
guides you through the process of formatting the disk for use
Keeping Track of Files
Computers have different file systems that allow them to locate and store files.
Windows uses FAT and NTFS Macs use HFS The operating system groups sectors
together to form clusters Addresses of clusters are kept in look up
tables called FAT (File Allocation Table for FAT computers) and MFT (master file table for NTFS)
Deleting Files
Generally when you choose to delete a file from your computer it changes the cluster’s status to empty
The data remains until a new file is stored there
File shredder software deletes data from the hard drive in a way that makes it difficult to retrieve
The Recycle Bin
The recycle bin, usually on the desktop, protect you from accidentally deleting files
To restore an accidentally deleted file, open the recycle bin, find the file, right click and choose restore.
Fragmented Disks When the operating system cannot store all of
the parts of a file together, it will locate other areas on the disk and store pieces here and there, causing fragmentation.
After awhile, lots of fragmented files will lower the speed of your hard drive as it moves to locate these pieces scattered across the disk
Periodically, you should run a defragmentation utility to rearrange the files in a more efficient manner. Right click on hard drive Choose Properties from the pop-up menu Click the Tools Tab Click Defragment Now….and wait quite some time
before it is done
Computer Viruses
Malicious code is a term used to describe a lot of types of programs that are intended to disrupt your computer’s normal functions
Includes viruses, worms, and Trojan horses written by hackers
What is a virus?
A virus is a set of program instructions that attaches itself to a file, reproduces, and spreads to other files
Viruses can corrupt data, destroy data, disrupt computer function, or display irritating messages
Viruses are many times spread to other computers via email and floppy disks
More on viruses….
Viruses may also deliver a payload in addition to replicating…ranging from destruction to screen graffiti
Some viruses infect and act as soon as they have access to your computer
Others wait for a trigger date or trigger event
Types of viruses
File viruses infect application files Boot sector viruses infects the
system files needed to turn your computer on
Macro viruses infect macros which are small programs, usually within application software, that carry out repetitive tasks
Trojan Horses
Trojan horses do not replicate itself Instead it appears as something that looks
like something else, maybe a graphics program or a file in an email
When executed, it searches your machine for password information
Can also include backdoors which allow hackers to access your computer remotely
Sometimes trojan horses are combined with viruses or worms causing a blended threat
What are Worms?
Worms are designed to spread from machine to machine, instead of file to file as viruses do
Some worms appear in emails and must be executed to be installed whereas others such as Sasser can actually travel networks without any action on the user’s part
What do viruses, Trojan horses, and worms do?
Various degrees of harm from annoying to very destructive
Network Traffic Jams are caused when worms are active and are taking a lot of network services
Denial of Service attacks cause a lot of computers to try and access a site at one time, bringing the web servers down
Browser reconfiguration reset your homepage and block you from accessing certain sites
More bad things….
Delete and modify files on your computer
Access confidential information such as usernames, passwords, banking info, etc.
Degrade performance of your computer
Retroviruses can disable anti-virus software and firewall software
How can I keep my computer safe?
Do not open executable files from email Check the links in emails before you click
to make sure the address is not redirecting you
Avoid file sharing software such as Kazaa Keep patches and updates to OS current Install and update anti-virus software
periodically
Anti-virus software
Anti-virus software is a set of utility programs designed to detect and remove malicious code
Checks all files for additional length, extra code in unused portions of existing programs, and by searching for known problems through the virus’s signature file.
Using Anti-virus software
Best case scenario is to leave your anti-virus program running all of the time in the background to scan all incoming files
Other than that, files should be scanned at least once a week
Signature files should downloaded every few weeks or when you read about a new threat
How reliable is virus software?
If used correctly, it is very efficient but not 100% protection against viruses.
Multi-partite viruses can infect various types of files on your computer and be difficult to delete
Polymorphic viruses mutate and change their code slightly to avoid detection with it’s signature
Stealth viruses remove their signature from disk and store themselves temporarily in memory
Virus Hoaxes You may receive emails or pop-up
windows at websites telling you about a new virus that you need to remove that are untrue
If unsure, contact Information Resources at 968-9885 or visit the website of your anti-virus vendor to search their database of known viruses.
Do not forward these messages on to others
Backing Up Your Data
You should backup data that is important to you to avoid accidentally overwriting or loss due to hardware failure
You can make backups, or copies, of important files to floppy disk, CD, DVD, or network storage areas such as your H: drive
Making Backups
Many computers come with backup software that allows you to backup everything on your computer (full-system backup) or just the files that are important to you
Once you’ve backed up your data, find a safe place to store the backup and keep them current as important files on your computer change.
If an accident or hardware problem occurs, simply restore the files from the backup copy.
What should I backup?
Any personal information or data files (Excel spreadsheet, word docs, etc.)
Internet connection information Email folders Email address book Your Favorites in browser Any downloads you may have paid
for, including music files
More tips…
Be sure and scan for viruses so you aren’t accidentally backing up viruses
Backup your data often enough to avoid a significant loss of data (determined by you what is significant)
Store backups in a safe place away from your computer
What should I backup to?
Depends on your computer and your pocket book, and the importance of the data
CD and DVD easy on many computers today Floppy and Zip disks may limit your backups
by lack of space Network and web space can many times
hold lots of data Second hard disk allows you to constantly
have two copies in case one fails Tape drives can copy large amounts of data
using backup software
Types of Backups
Full backup-as the name implies, it backs up everything on the disk
Differential backups makes a backup of files that have changed or been added since the last full backup.
Incremental backups make backups of files that have changed or been added since the last back up, regardless of the type of backup
Boot and Recovery Disks Sometimes the very kernel of your OS is
corrupted and needs to be repaired Many systems ship with a recovery disk that
restores the OS to it’s original factory settings If not, recovery CDs can be created using the
Automated System Recovery Wizard in the Backup Utility of Windows XP
Boot disks, either on floppy or CD, contain the operating system files needed to boot your computer without accessing the hard disk
Boot disks can also be created by right clicking the A: drive and choosing Format, under which has an option to create an MS-DOS start up disk