Knowledge

Monday, November 29, 2010

What is COMPUTER SCIENCE


Computer science or computing science (sometimes abbreviated CS) is the study of the theoretical foundations of information and computation, and of practical techniques for their implementation and application in computer systems.[1][2][3][4] It is frequently described as the systematic study of algorithmic processes that create, describe, and transform information. Computer science has many sub-fields; some, such as computer graphics, emphasize the computation of specific results, while others, such as computational complexity theory, study the properties of computational problems. Still others focus on the challenges in implementing computations. For example, programming language theory studies approaches to describe computations, while computer programming applies specific programming languages to solve specific computational problems, and human-computer interaction focuses on the challenges in making computers and computations useful, usable, and universally accessible to people.
The general public sometimes confuses computer science with careers that deal with computers (such as information technology), or think that it relates to their own experience of computers, which typically involves activities such as gaming, web-browsing, and word-processing. However, the focus of computer science is more on understanding the properties of the programs used to implement software such as games and web-browsers, and using that understanding to create new programs or improve existing ones.

HOW TO BACKUP YOUR FILES IN YOUR COMPUTER

Why is it important to backup your files?
•    Computer Hard Drives are a mechanical device, they do fail!
   •    Power outages/blips
   •    Hardware failure
   •    Viruses
•    Comfort Level : So you know you have them in a safe place!
•    TAC does not backup your data on your hard drive(s)!
•    When/if TAC or our external vendor (Computer Showcase) replaces your hard drive or delivers a new system, we will do our best to migrate what data is in the My Documents folder but we cannot guarantee everything will be migrated.
Windows Backup is Simple to Use and Schedule
•    It comes with the Windows Operating System
•    It creates a container file that can be stored on most any removable or external storage device
•    You can use Windows Backup to Restore any or all files to any storage device.
•    It retains the file ownership and dates
•    It can be used in a easy to follow ?Wizard? mode


Windows Backup Utility - Backing Up Your Data
To access Windows Backup choose "Start-Programs-Accessories-System Tools-Backup"
The following screen will appear:
Click "Next" to run Windows Backup in Wizard Mode


Do you wish to Backup or Restore data files?
Click on the Back up files and settings radio button and click "Next".
For this training session we are going to choose "My documents and settings" which will include everything in the My Documents folder of the account that is logged in as well as the favorites, desktop icons and any cookies that may be available. Click this radio button and click "Next".




•    Choose the target location where you would like to store your backup data by either clicking on the down arrow and choosing an available drive letter or ?Browse? to find a network share or other location. Note that Windows Backup cannot write directly to a CD or DVD disc.
•    Type in a name for the backup container file you will create. You can give it any file name you wish. For this example we will change it to :
   •    My Documents and Settings Backup - mm-dd-yyyy
Click "Next"
That is it! These 5 screens are all you need to create your first backup container file. If you do not wish to schedule this backup to run at set dates or times, then click ?Finish? and the backup process will begin running. If you would like to schedule the backup to run at specific times then click on the "Advanced" button.
Advanced Options for Windows Backup

Types of backup

The Backup utility supports five methods of backing up data on your computer or network.

A copy backup copies all selected files but does not mark each file as having been backed up (in other words, the archive attribute is not cleared). Copying is useful if you want to back up files between normal and incremental backups because copying does not affect these other backup operations.
A daily backup copies all selected files that have been modified the day the daily backup is performed. The backed-up files are not marked as having been backed up (in other words, the archive attribute is not cleared).
A differential backup copies files created or changed since the last normal or incremental backup. It does not mark files as having been backed up (in other words, the archive attribute is not cleared). If you are performing a combination of normal and differential backups, restoring files and folders requires that you have the last normal as well as the last differential backup.
An incremental backup backs up only those files created or changed since the last normal or incremental backup. It marks files as having been backed up (in other words, the archive attribute is cleared). If you use a combination of normal and incremental backups, you will need to have the last normal backup set as well as all incremental backup sets in order to restore your data.
A normal backup copies all selected files and marks each file as having been backed up (in other words, the archive attribute is cleared). With normal backups, you need only the most recent copy of the backup file or tape to restore all of the files. You usually perform a normal backup the first time you create a backup set.
Backing up your data using a combination of normal backups and incremental backups requires the least amount of storage space and is the quickest backup method. However, recovering files can be time-consuming and difficult because the backup set can be stored on several disks or tapes.
Backing up your data using a combination of normal backups and differential backups is more time-consuming, especially if your data changes frequently, but it is easier to restore the data because the backup set is usually stored on only a few disks or tapes.
We recommend just choosing a type of NORMAL and each time this runs the complete set of data will be backed up and although this creates the largest size of backup files it is the easiest to restore.
Choose Normal and Click "Next"
•    Verifying your backup will double (or more) the total time for the backup to complete but if you wish to make sure all your data is completely read and written to the destination area you could click this box.
•   ; NOTICE: we have had some backup routines fail unless the Disable volume shadow copy box is checked. If it is checked, then at the time the backup routine is running, any files that you may have open will not be copied. This is normally not an issue because most users will schedule backups to run during non-work hours so we recommend that you DO CHECK this box.
Check the Disable volume shadow copy and click "Next"
We recommend that you replace the existing backups otherwise you will continue to use up more and more disk space and the backups will eventually fail. Plus, since we recommend the type Normal backup there is no need to continue appending the data to a full normal copy you previously made anyway.
Click the Replace the existing backups radio button.
Check the Allow only the owner and the Administrator access to the backup data and to any backups appended to this medium so that only you have access to this data. Most any file that gets stored on external storage can be viewed by anyone who logs into the machine so this option is essential. In addition, the administrator should be allowed access in case you cannot get to this backup data file as a safe guard in the event of any unforeseen issues.
Check this box and click "Next"
Click on the Later radio button click on the Set Schedule Button to schedule when this backup will run.
Choose Weekly and a start time (after hours preferably) and schedule it to run every week (we recommend Tuesday - Friday) but choose other days if your data changes on other days. Click OK to continue.
You will be prompted to enter a username and password, enter your EUP\USERNAME and password and confirm it so this process can run under your credentials. Click ok and this will bring you back to the previous backup wizard screen.
Click "Next" (you may be asked to enter your username and password once again, we do not know why this occurs but enter it one more time and click OK).
Congratulations! You have configured and scheduled your backup process to run unattended. Click FINISH to exit the wizard.
NOTE: You can view your schedule job and get a status by going to Start-Settings-Control Panel and double clicking on the ?Scheduled Tasks? icon and reviewing the Next Run Time and Last Run Time of your scheduled task to ensure that it is still scheduled to run.
IMPORTANT NOTE: Due to a security design in the Windows Operating System, you must remain logged in for scheduled tasks to execute. We recommend that you LOCK your system when you leave or walk away from your office. You can do this by pressing CTRL-ALT-Delete keys and clicking on the Lock Computer button or a quicker way is to just hold down the Windows key and press the L key. You will still be logged in and only you can "unlock" the system with your username and password. We also recommend powering off your monitor (but not your system of course) when you leave at the end of the work day.

Windows Backup Utility - Restoring Your Data
To access Windows Backup choose "Start-Programs-Accessories-System Tools-Backup"
The following screen will appear:
Click "Next" to run Windows Backup in Wizard Mode

Do you wish to Backup or Restore data files?
Click on the Restore files and settings radio button and click "Next"
You can select an entire backup container file to restore or expand the list of backup files by double clicking on the name in the left window pane. You can expand through the levels to find the folder(s) you need and then in the right window pane you can check the folder(s) and/or file(s) you need to restore. Note a red exclamation mark on any folder(s) or file(s) depicts that a file exists that was not copied during the backup process. More than likely this scenario exists because the file was in use by some other application when the backup process tried to copy it.
Click "Next" once you have selected the data you need.
At this point you can click the Finish button and the restoration process will begin to restore the folder(s) and file(s) you choose.However, if you wish to change where and how the files should be restored and the security settings then you can click on the Advanced button. By default the restore function will check to see if the file(s) exist and compare them and only restore them if they are newer than any existing files with the same name. This is normally all that you would need. We will not go through the advanced settings in this document but feel free to review these when you run the restore process by clicking on the Advanced button.
Once you click the finish button, the restoration process status window will pop up and show you the ongoing status. When the process completes, the status window will display an option to review a report of what was done. This is a useful report to review especially if there are errors with the process. Feel free to experiment with smaller data files to restore by choosing various advanced settings and reviewing the reports that are created. For example, you may have some data files that you want to restore to a removable USB key rather than placing them back on your local hard drive, choose the advanced button and route the destination to your USB drive. Enjoy.

How to reformat your computer/windows xp

Reformat Your Computer Disk Drive

Why Should You Reformat Your Computer?

There might be a point in time when your computer frustrates you so much despite the time and effort you have invested to fixing a damaged software or removing a virus to no avail. Or perhaps, you have tried all sorts of ways to revive your system but it still runs so slowly. Generally, unless we have expertise knowledge on certain areas of troubleshooting, some problems can be difficult to resolve. When this happens, reformatting your computer usually helps. A clean reformat eradicates all problems and brings your computer back to a 'healthy' state!

Understanding Reformatting And Its Causes

It's important to understand that a full formatting clears everything in your hard disk, checks and mark bad sectors and installs a fresh new working operating system. You get to start over, getting rid of old data, leftover files, and unused programs that were cluttering your hard disk. Therefore, backup any important files, especially those that reside in MY DOCUMENTS folder. Because once you format your computer, you might have a hard time saving those files which you might have missed out on backing-up even with data recovery.

What Should You Prepare Before You Start

It's exciting to know that a brand new system awaits you - a virus-free and corruption-free speedy computer. Now before you start, determine if you have the necessary items because if you don't, you might have a hard time fixing certain issues once your system is up.

The following is a must-have before you start:

  1. Windows operating system installation disc with CD-KEY
  2. Device Drivers
  3. Antivirus software
If you do not have all these items (perhaps you have thrown some of them away accidentally), an alternative is to download these drivers from the Internet. Log on to the manufacturers' website and visit their SUPPORT section. Most drivers, utilities and troubleshooting materials are usually posted under that section.

If you do not know the brand and model of your device, you can check using the System Information utility. To do so, follow these steps:

  • Click Start, point to Programs, point to Accessories
  • Point to System Tools and select System Information
  • Explore under the System Information group list to identify the devices

Once you have downloaded the necessary drivers and tools into your computer, transfer them into a removable drive such as a CD-R or a floppy disk.

Reformat Your Computer (using WinxP as an Example)

Set your BIOS to boot from CDROM

To do this, follow these steps:

  • Restart your computer
  • Hit the DEL button or any key that enters the BIOS
  • In the BIOS menu, enter the Boot Sequence from the Advanced BIOS option
  • Select CD-ROM to be the first bootup device and HARD DISK to be second
  • Save settings and exit the BIOS
  • Insert Windows XP CD and restart the computer
After you restart the computer, a message will prompt you to boot from CD. Hit any key.

For all screenshots, click on image to view bigger version


Now, a blue screen will appear and begin loading XP setup from the CD


Hit Enter to setup Windows XP


After agreeing to the EULA, hit F8


Select the drive to install Windows XP, then hit Enter

Select Format the partition using NTFS File System(Quick)
Note: NTFS generally provides better security and reliable file system for Windows XP. Let's do a quick comparison and analysis to determine which file system is best for your system.
FAT32 is helpful if you're intending to install a dual operating system. It supports a partition up to a maximum of 32 GB and the maximum size of a file is limited to 4GB. Provides better performance if you have partitions that are 2GB or less.
NTFS provides file security, compression and encryption. It supports a maximum file size up to its disk volume. Generally runs faster on larger disk with quick boot up time. It is incompatible with Windows Millennium and all older versions.


System will format the partition and the installation files will be copied.


The computer will reboot.


Setup commences.


The first form that appears is the Regional And Language Options. Determine your preferred settings and click Next.


You will be prompted to enter your Name & Organization.


Next, enter your Windows XP CD-Key. This key is usually attached with the CD jewel case or license. After that, click Next.


Now, enter an computer name. Click Next

You'll now be prompted to configure your Date & Time Settings. Make the necessary changes and click Next.


Next, you'll be prompted to select a network setting. Select Typical Settings and click Next. Click Next again.


Windows XP Setup resumes its installation.


After Windows XP is setup, you can now install all your device drivers and application software and restore any backup files and you're almost done!


All Screen Captures Courtesy of The Elder Geek on Windows XP
Source: http://www.theeldergeek.com

Windows 7 features and functions

The Windows 7 operating system shares many features and functions with Windows Vista. It also improves on Vista. Here is a list of features and functions that are unique to Windows 7:

Action Center – allows users to see what alerts Windows 7 shows; a handy way to control those annoying UAC messages while not having to disable it.

Explaining the Windows 7 Action Center

Windows 7 Action Center
Using the Action Center
Action Center consolidates and gives you control of all Windows 7 message alerts. It allows you to configure what messages you do and do not see from Windows maintenance and security, including Windows Defender and User Account Control.
When Windows 7 requires your attention, the Action Center icon appears on the taskbar. If you click the icon, you will see the alerts and suggested actions for any issues listed.
Within the Action Center:
  • Red items are labeled Important - indicate issues that should be addressed as soon as possible (like outdated anti-virus program).

  • Yellow items are suggested tasks - like recommended maintenance tasks.
To view details about either the Security or Maintenance section, click the heading or the arrow to expand or collapse the section. If you don’t want to see certain types of messages, you can choose to hide them from view. If Windows pop-up balloon messages bother you, you can customize those settings as well in the Action Center.



Aero Shake – click and shake one open window and all others on the desktop will minimize.
Aero Snap – drag a window to any edge of the display and it will automatically re-size.
Aero Peek - point to the right edge of the taskbar to watch open windows turn transparent, revealing all your hidden icons and gadgets

Introducing Aero Peek - a Fast Way to View the Desktop

Windows 7 Aero Peek
Windows 7 Aero Peek
Aero Peek allows a user of Windows 7 to peek through all open windows to the desktop underneath. Point the cursor on the right edge of the taskbar - open windows instantly turn transparent, revealing all icons and gadgets on the desktop.
To quickly show a hidden window, point to its taskbar thumbnail; only that window appears on the desktop.
Aero Peek is included in Windows 7 Home Premium, Professional, and Ultimate editions.
 
Aero Templates, Themes – new backgrounds and themes unique and created for Windows 7 (including free additional themes downloadable from Microsoft).

Themes and Backgrounds Available with Windows 7

windows 7 themes backgrounds
New Windows 7 Themes
This feature lives up to the hype: The work Microsoft has done is stellar. There are an awesome collection of Backgrounds and Themes included with Windows 7 and others you can download free. Also, the new desktop slide show can display a rotating series of pictures (either yours or Microsoft’s) - yet one more reason to like the Aero interface.
Check out the available Themes and Backgrounds on Microsoft's web site for more information.

Device Stage - helps users interact with any compatible device connected to a Windows 7 computer; view device status and run common tasks from a single window. The key words here are "compatible devices."
  • Domain Join – helps business users quickly connect to different office networks.
  • Gadgets (Improved) – the Sidebar has been eliminated; Gadgets can be placed anywhere;
 New Gadgets have more functionality.
  • Home Group – enables users to quickly and easily create home networks between computers using Windows 7.
  • An Easy Way to Setup Home Network Sharing - HomeGroup

    Windows 7 HomeGroup
    Windows 7 HomeGroup
    HomeGroup takes the complexity out of sharing files and printers on a home network. HomeGroup makes it easy to connect two or more PCs running Windows 7 and automatically share music, pictures, video, and document libraries with others.
    HomeGroup is also password-protected: After HomeGroup has been setup on the first computer, it generates an alphanumeric password that other computers will use to connect – if the password is not right, there will be no connection.
    The user decides what gets shared and what stays private. Files can be marked "read only," so others can see but not edit or delete data.
    Users can join a HomeGroup with any edition of Windows 7, but only users with Windows 7 Home Premium, Professional, or Ultimate can create a HomeGroup. Also, it does not work with other versions of Windows – only Windows 7 computers.

  • Jump Lists - right-click a program icon and see a list of recently used files that use that program.
  • A Faster Way to Find Your Stuff

    windows 7 jump lists
    Windows 7 Jump Lists
    Jump Lists (new in Windows 7) is a quick way to take you right to the documents, pictures, songs, or websites you use each day. This feature is an updated version of the “Recent Items” feature and is now included in the right-click menus of programs and shortcuts.
    To open a Jump List, right-click on a program in the Windows 7 Taskbar or Start Menu. You will see a Jump List (titled "Frequent") of the latest items opened with that specific program. This feature is a real time saver.

  • Libraries - make it easier to find, work with, and organize documents, music, pictures, and videos scattered across your PC or network.
  • Using Windows 7 Libraries

    windows 7 libraries
    Windows 7 Libraries
    In previous versions of Windows, users managed files by organizing them in different folders and sub folders. In Windows 7, libraries can be used to organize and access files regardless of where they're stored.
    A library gathers files from different locations (different folders, computers, hard drives) and displays them as a single collection, without moving them from where they're stored.
    There are four default libraries (Documents, Music, Pictures, and Videos). Users can also create new libraries or modify existing ones to suit their needs and share them with people in your Home Group. Within a library items can be ordered by folder, date and other user-chosen properties.

  • Location-Aware Printing – if you travel between offices or home and office, this feature is handy: Windows 7 remembers which network and printer you're using and automatically switches the default printer to match the one you last used.

  • Multiplayer Games – Microsoft has revived 3 XP multiplayer games: Internet Checkers, Internet Spades, and Internet Backgammon.
  • Microsoft Brings Back Favorite Games From Vista and XP

    Windows 7 Games
    Windows 7 Games
    In Windows 7, Microsoft has brought forward successful games from Vista and revived several multi-player games from Windows XP. The list of games for Windows 7 includes:
  • Chess titans

  • FreeCell

  • Hearts

  • Mahjong Titans

  • Minesweeper

  • Purble Place

  • Solitaire

  • Spider Solitaire

  • Internet Backgammon

  • Internet Checkers

  • Internet Spades

All three of the multi-player games are included in the Home Premium, Professional, and Ultimate editions of Windows 7.
Also provided in the Game Explorer is a link to more games from Microsoft.
  • Networking (Improved) – improved task bar widget that allows for quick network connection and configuration.

  • Play to function - right-click the music tracks you’d like to hear and select Play To. Play To works with other PCs running Windows 7 and devices compliant with the Digital Living Network Alliance (DLNA) media standard. 
  • Task Bar (Improved) - "pin" favorite programs anywhere on the taskbar; rearrange programs in any way you like by clicking and dragging. Point to a taskbar icon to see a thumbnail preview of open files or programs. Then, move your mouse over a thumbnail to preview the window full-screen.
  • Using the Taskbar

    windows 7 taskbar
    Windows 7 Taskbar
    The Windows 7 taskbar is the horizontal bar at the bottom of the screen. The taskbar can usually be seen, regardless of the open program or file. It provides quick access to applications, information and open files even if the desktop is obscured.
    The taskbar has three main sections:
  • The Start button - opens the Start menu.

  • The middle section – Quick Launch icons that can start applications and hold open files and programs. You can "pin" favorite programs anywhere on the taskbar; rearrange programs in any way you like by clicking and dragging. Point to a taskbar icon to see a thumbnail preview of open files or programs. Then, move your mouse over a thumbnail to preview the window full-screen.

  • The notification area - the clock/date and icons that communicate program status, computer settings and the Aero Peek Button.


  • Windows Media Center (Improved) – a few new features and integrates with Home Group.

  • Windows Media Player 12 – An upgrade from version 11 that plays the most popular audio and video formats—including new support for 3GP, AAC, AVCHD, DivX, MOV, and Xvid; also available by download, no doubt.

  • Windows Touch – support for computer touchscreens.

  • Windows XP Mode – Allows an XP session of Windows to run so that Business applications will work within Windows 7 – however, will not work with most current Intel and some AMD-based computers.
  •