Some Good Computer Habits to have

You've always been taught to cultivate good habits and avoid bad ones. The same applies to your computer use, where habits are good, bad or ugly. Good habits can maximise your IT investment and optimise your operational efficiency, while bad ones can cost you money and slow you down. The ugly ones can lead to disaster and an ugly mess. Here’s a list of computer habits you should kick start into your regular routine to keep you going – in the right direction!

1. Save frequently: To avoid any data loss in case of software or system freezing, regularly save your changes to documents. Doing so only takes a second and won’t interrupt your productivity groove. Use the keyboard shortcut “Ctrl + S”, or click on the “Save” icon – the old floppy disk in the toolbar. Don’t rely on “ Auto Save”, as it’s not a feature on every program.
2. Backup: Don’t risk losing your files by not having them backed up. With damage, loss and theft all possible, no hard drive is guaranteed to be functional forever. Recovering data is often impossible and more costly and time consuming than people think. Tireless efforts on work-related documents can be preserved by simply copying files to a few DVDs, USB drive or portable hard drive, at regular intervals.
3. Think before you print: A hard copy is required sometimes, but not every time. So before clicking “Print”, determine if you really need to hold a copy of the document in your hand. And if you do, do you really need the entire thing? Use “Print Preview” and the option of selecting a “Page range” to print only the pages you actually need. And use the double-sided printing feature where available – to print multiple pages onto only one sheet of paper. It would also be helpful to set your printer to print in black and white by default, manually choosing colour prints only when necessary. All of these printing habits will have a positive impact on your environmental initiatives and can save you money by using less ink and paper.
4. Structure folders: Where do you save your files? Is everything scattered all over the desktop or stuffed into the “My Documents” folder? Maintain some order by creating folders and subfolders while giving your files appropriate names. It will only take a few extra seconds to do so, but will save you much more time in the future by being able to easily find and sort through files.
5. Store software keys: Make a note of software licence keys and store them safely. In the event of your needing to re-install or activate a program, having its corresponding licence key handy can be the difference between completing a simple re-installation and having to go out and purchase a new one.
6. Invest in security software: Protect your IT investment, your hard work and yourself! Viruses, spyware, adware and other malicious software are topics in the news for a reason. These threats can infect your computer without your even realising it. But do you know what kind of damage they can cause? They can delete or damage files, track your online activity, steal personal information and just outright annoy you by having a poorly performing computer. Take action before they do by investing in sufficient security software. When you do, keep the software up to date and scan your computer regularly to maintain optimum performance and productivity.
7. Blink. Yes, with your eyes: Staring at a computer screen for extended periods of time can have a negative effect on your precious eyesight. Computer users tend to blink less frequently, so make it a habit to blink more often. Why? Blinking produces tears that coat the eyes, keeping them lubricated and moist. Other habits to preserve and protect your eyesight include focusing on distant objects every 15 minutes to relax your eye muscles, and to just take a break every hour or two to reduce eyestrain. Your eyes will thank you.

3D printing: the future of manufacturing at home?

What is 3D printing?

Imagine designing a component on a computer and having a prototype emerge from your printer. 3D printers and desktop manufacturing technology are making this an affordable reality.

3D printing is a form of additive manufacturing technology where a three-dimensional object is created by laying down successive layers of material. 3D printers are generally faster, more affordable and easier to use than other additive manufacturing technologies; they offer both product developers and hobbyists the ability to print parts and assemblies made of several materials with different mechanical and physical properties in a single build process. Advanced 3D printing technologies yield models that can serve as product prototypes.

These printers can build incredibly complex things, from finely detailed art, to devices with moving parts. Traditional prototyping methods tend to use epoxy or quick-hardening plastic to make solid objects, while 3D printers work with a greater variety of materials. For example, even relatively simple devices can use plaster, Play-Doh, silicone, wax (to make forms for casting), low-melting point metals and various other materials (although this can become expensive).

The power of production

The real power of 3D printing is that consumers can have just about anything they want – especially if they have the skills themselves to create 3D models. But even if they don’t, they can pay a company to create the digital files, describe what they want and, within a matter of weeks, the printed object, or objects, will arrive in the post. Some companies even offer a next-day service: send in a design request and receive your prototype by courier the very next day.

Right now, 3D printing is at the stage where personal colour printers and laser printers were twenty years ago. But the technology is evolving rapidly, and costs are plummeting. You can find small, affordable 3D printers online, although these are hobby machines that require assembly and some technical knowledge.

Quality at home

Of course, at the moment, the build quality of today's 3D printers (at least the semi-affordable ones) is not quite equivalent to mainstream manufacturers. Objects that have been professionally designed are tested and certified for safety, but a homebrewed object probably has not. The build chamber of many 3D printers is smaller than the object someone would want to print, therefore parts must be printed and then assembled. In some cases, this could be difficult.

The holy grail for some of the small 3D printing start-up companies is to create a 3D printer that can print itself, allowing anyone to give the power of production to anyone else.

In the future, you’ll probably be able to print out consumer goods immediately. Imagine printing out a brand new coffee table (some assembly required), a mug, a set of cutlery, or even a pair of trousers. Eventually, 3D printers might be able to create electrical circuitry, meaning that consumers could download a design for a toaster or perhaps a new cellular phone. This could change the way we look at copyright, counterfeiting and even the concept of authenticity – we may see a revolution in consumer goods similar to the digital revolution of recorded music and film.

The world is being turned upside down: imagine recycling plastic at home so that you can print out new products? We're almost there.

Demo Videos

Advantages & Disadvantages of Computer Networking.

Advantages

• Resource Sharing : We can share software resources as well as hardwares such as printer, fax machine etc.
• Centralized Data Management : Data can be stored and managed on a special computer(Called a File Server). Users can access it anytime from their computers through the network.
• Centralized Administration : A group of computers in a network can be administered from a singe machine.
• The Internet : The evolution of Internet is the most significant advantage of networking. It is highly influenced in the day to day activities of us nowadays. Email, Social Networks, Chat, Online Business are some of the major usages of Internet.

Disadvantages

• Most networks requires additional Hardwares and Softwares which are costly.
• Network or Server faults may lead the users to loss their resources.
• Need Administrator(s) or sometimes Experts to manage and maintain a network.
• Virus affection and spreading chances are very high when computers are connected in a networks.
• Computers connected to a public network is open to Hackers. We need to implement explicit security measures to protect our computers which are costly.

Repairing the ntldr missing problem - Windows XP/2000/2003

Here is how a Windows XP machine can recover from the ntldr missing problem.

Figure 1 shows the typical error message of the problem:

Fig: 1

Step1:

Boot the machine using Windows XP bootable CD. After sometime the setup shows options like Figure 2:

Fig: 2

Step2:

Here, press R to enter the Recovery Console. When you entered, the recovery console will display the windows directories in your system and asks for your choice. See Figure 3:

Fig: 3

Here, enter the option number (Eg: 1) of your windows directory. Now, you will be asked to enter the administrator password of your OS. Enter it to get access to the repair console. (Ref: Figure 4)

Fig: 4

Step3:

Now you have access to some windows commands here. We just need to restore the missing files to the installation drive. For that, enter the following commands in order.

1. copy D:\i386\ntldr C:\
   (Here D is the CD drive )
2. copy D:\i386\ntdetect.com C:\
3. attrib + rhs C:\ntldr
4. attrib +rhs C:\ntdetect.com

Fig: 5

Type exit command to restart your machine.
That is all, Enjoy..
For a better reference, watch the demonstration video here:

NB: This method works only if your system is not booting because of losing ntldr or ntdetect or both files..

Mozilla Firefox Mouse Shortcuts.

   Ctrl + Scroll Up                              :           Zoom In

   Ctrl + Scroll Down                         :           Zoom Out

   Double-Click on Tab Bar              :          New Tab

   Middle-Click                                   :          Scroll Lock

   Middle-Click on Tab                      :          Close Tab

   Shift + Scroll Up                             :          Forward

   Shift + Scroll Down                        :          Back

   Shift + Left-Click                            :         Open in New Window

   Shift + Reload Button                    :         Reload but Overrides Cache

   Ctrl + Drag                                      :         Copy Tab or Bookmark

   Alt + Left-Click                               :         Save Page As

   Alt + Scroll                                      :         Scroll line by line

Mozilla Firefox Keyboard Shortcuts

Ctrl + N                                        :     Open New browser window.
Ctrl + P                                         :     Print current page / frame.
Ctrl + T                                        :     Opens a new Tab.
Ctrl + F4 or Ctrl + W                  :     Closes the currently selected tab.
Ctrl + Shift + W or Alt + F4        :     Close the current window.
Ctrl + Shift + T                            :     Undo the close of a window.
Ctrl + Tab or Ctrl + Page Down  :     Go to next Tab(Left to Right).
Ctrl + (1 to 8)                               :     Select Tab from 1 to 8.
Ctrl+9                                           :     Select Last Tab.

Ctrl + Shift + Del                         :    Open the Clear Data window to quickly clear private data.
Ctrl + D                                        :     Add  Bookmark for the page currently opened.
Ctrl + I                                         :     Display available bookmarks.
Ctrl + J                                         :     Display the download window.
Spacebar                                      :     Moves down a page at a time.
Shift + Spacebar                          :     Moves up a page at a time.
Alt + Down arrow                        :     Display all previous text entered in a text box and/or available options on Drop down menu.
Alt + Left Arrow                          :     Back a page.
Backspace                                    :    Back a page.
Alt + Right Arrow                        :     Forward a page.
F5                                                  :    Refresh current page, frame, or tab.
F11                                                :    Full screen mode.
Esc                                                :    Stop page or download from loading.
Ctrl + (- or +)                                :    Increase or decrease the font size, pressing '-' will decrease and '+' will increase.
Ctrl + Enter                                  :    Quickly complete an address. For example, type google in the address bar and press CTRL + ENTER to get http://www.google.com.
Shift + Enter                                 :    Complete a .net instead of a .com address.
Ctrl + Shift + Enter                      :    Complete a .org address.

Classifications of Networks-Part 4

Networking Models

Peer-to-Peer(Workgroup) Model

Peer-to-Peer Model

Peer-to-Peer or simply P2P is a networking model in which each computer in the network has the same priorities or rights when communications are done. That is there is no central nodes or namely servers to manage and control other nodes in the network.  In some cases, peer-to-peer communications is implemented by giving each communication node both server and client capabilities. Because of  these reasons, the P2P is a less secure networking model.

                                            The Peer-to-peer model is also known as Workgroup Model, because the computers working in this model are said to be lied in a Workgoup (A group of computers).

Advantages

1. Easy to setup the network.
2. No dedicated nodes needed.
3. Less expensive.
4. Suitable for small networks with ten to twenty nodes.
5. Local users can control their shared resources.

Disadvantages

1. Less Secure.
2. Less Reliable.
3. Difficult to Administrate.

Client-Server(Domain) Model

Client-Server Model

This is a much secure networking model compared to P2P. In a server-client network, there must have a special computer called server and the others will be clients. A Server is typically a computer which provides service, but here we are using the term server to denote a specific node which has the ability to control and manage other nodes which we calls as clients. Clients are nodes which receives services from a server.

                                 In most conditions, servers only gives some software resources(or a Database) for the clients to use their computer under the control of the server and do their work that are allowed by the server. That is most servers are not intended to give their processing capability or storage capacity to clients. All these resources should exist in the client computer itself.

                The servers must have specific server operating systems installed on it.Some popular server OS's are Windows 2000 Server, Windows 2003 Server, Windows 2008 Server, Redhat Enterprise Linux, Ubundu Server. Clients only need any desktop level OS such as Windows XP, Windows Vista, Windows 7 or Ubundu Desktop.

Advantages

1. Having a dedicated high end machine as server will increase the network performance.
2. Highest level of security(Centralized control of data).
3. Highly expandable.
4. Easy administration compared to P2P.
5. More reliable than P2P.

Disadvantages

1. Server should be dedicated with high configuration hardwares and specific networking softwares(including OS).This is expensive.
2. Server should always be available.
3. Need a full time administrator to maintain the network.
4. Maintenance also is expensive.

Classifications of Networks-Part 3

Network Topologies

                                 A network Topology means, the physical arrangement of computers,devices and cables in a network.

Bus Topology  

In Bus topology network devices uses a common backbone in a linear shape to communicate in the network. All the devices should be attached with this single shared cable with an interface connector. The device, which wants to communicate send a broadcast message to all the devices attached with the shared cable but only the intended recipient will accepts and process that message.

Bus Topology

Advantages

1. Easy to setup a network.
2. Easy to expand.
3. Suited topology for small networks.
4. Less expensive compared to other topologies.                                  

Disadvantages

1.  Slower data transfer rate.
2. Cable length and number of nodes that can connected are limited.
3. If the backbone cable fails, the whole network will fails.
4. Heavy network traffic when number of nodes are increased.

Ring Topology 

Ring Topology

In this topology computers are arranged in a ring manner. That is every computer or devices in this network should have two neighbors for communication. All the communications will be in the same direction, either clockwise or anti-clockwise. 

                              FDDI (Fiber Distributed Data Interface) or Token Ring Technology can be used to implement Ring Technology. Ring topologies can be found in office, school or small buildings.

Advantages

1. Chances of collision is very low.
2. Better performance than a Bus topology.

Disadvantages

1. Failure of one computer or port can cause the whole network to fail.
2. Adding, moving or removing devices can affect the network.
3. Slower than Star topology under normal load.
4. It is difficult to troubleshoot a ring network.
5. Network cards are expensive compared to Ethernet cards and hubs.

Mesh Topology

Mesh Topology

In a mesh topology, each device in the network are interconnected to one another to provide an almost always up network connectivity. That is each device remains in the network even if one or two of the connections go down. As this topology is difficult and expensive to configure, it is not commonly used in most computer networks.

Advantages

1. Data can be transmitted from one node to many nodes and vice versa simultaneously.
2. Less traffic problems.

Disadvantages

1. Configuration of network is complex and expensive.
2. Difficult to manage the network.

Star Topology

Star topology is the most commonly used topology in LAN. A star topology links the computers by individual cables to a centralized connectivity device, usually a hub or switch. The commonly used cable is the Unshielded Twisted Pair (UTP) or Shielded Twisted Pair (STP).

Star Topology

Advantages

1. Easy to setup and expand the network. 
2. Adding, moving or removing devices will not affected to the entire network.
3. Better performance than other topologies.                  
4. Failure of one device or link will not affect the whole network.
5. Centralization of network will help to analyze the traffic.
6. Easy to troubleshoot.

Disadvantages

1. Dependency to the central device(Hub or Switch) is the main drawback. If it fails, the entire network goes down.
2. Expansion and performance of the network is depended on the capacity of the central device.
3. Need of the expansion devices(Hubs, Switches or Routers) will make the network expensive.

Classifications of Networks-Part 2

According to Geographical conditions

• LAN (Local Area Network) : A Local Area Network covers only a localized or small physical area such as Home, Office, building or a small groups of building such as a school, or an airport.A LAN is useful for sharing resources like files, printers, games or other applications. A LAN in turn often connects to other LAN's, and to the Internet or other WAN.Most local area networks are built with relatively inexpensive hardware such as Ethernet cables, Network adapters, and Hubs/Switches. Wireless LAN and other more advanced LAN hardware options also exist.

Local Area Network

• MAN (Metropolitan Area Network) : A MAN is simply a network which interconnects a number of  Local Area Networks (LAN's) using a high-capacity backbone technology, such as fiber-optical links and spans a city or a large campus. A MAN often provides

Classifications of Networks - PART 1

                                    Networks can be classified into many according to its different characteristics. We can mainly divide networking into two categories,

• Wired Networking :  Wired networks are established by connecting computers or devices using some type of networking cables such as UTP (Unshielded Twisted Pair). Wired networks provide users with plenty of security and the ability to move lots of data very quickly. Wired networks are typically faster and reliable than wireless networks, and they can be very affordable. A notable drawback of wired network is that the cost of cables will make it expensive when more computers are added to the network. It can also make problems with the wires, because it can greatly limit the mobility of devices.

Wired Network

• Wireless Networking : Wireless networks are those which uses radio waves instead of cables to for computers to communicate. It is easiest and least expensive way to connect the computers, but slower and less secure compared to wired. They are more flexible than the wired networks because of the absence of physical wires.

Wireless Network

Mozilla Firefox Master Password

To help secure your password information from anyone else using Firefox or from anyone that could steal your computer follow the below steps to setup a Master Password.

1. Open Firefox and click Tools and then Options.
2. From the Options window, select the Security tab.
3. Check the Use a master password option.
4. Enter your master password and click OK. From now, no one without having the master password can neither View or Delete the saved passwords nor can Add new passwords to the list.

To view or delete Saved Passwords click the Saved Passwords button on the Security tab and then click Show Passwords option. Enter your master password and you can see the passwords.

Lock your personal folder without using any software.

First, locate the folder which you want to lock. Suppose, DATA is your private folder and it is stored in D:\ drive.

In the same drive ( ie, D:\) you need to create a batch file. For this, Do the following steps:

1. Open Notepad, Start>Programs>Accessories>Notepad
2. Type, ren data data.{21EC2020-3AEA-1069-A2DD-08002B30309D}
3.  Now, take File menu and click Save  (The Save As window appears)
4. Here, Select D drive in the Save in option and give File name as "Lock.bat" (with quotes)
5. Click Save and close it.

Now open D drive where your folder DATA is, there should be a file named Lock, Double click it. Now the folder DATA's icon will be changed to Control Panel icon.
Try to open the folder DATA, it will open the Control Panel instead of your folder. It is Locked!!


To Unlock

To create another batch file.(Do this only when necessary and delete after use.)

1. Open Notepad, Start>Programs>Accessories>Notepad
2. Type, ren data.{21EC2020-3AEA-1069-A2DD-08002B30309D} data
3.  Now, take File menu and click Save  (The Save As window appears)
   
4. Here, Select D drive on the Save in option and give File name as "Unlock.bat" (with quotes)
5. Click Save and close it.

Now, Open D drive and Double click on unlock.bat and you will get back your original folder.

NB: Try at your own Risk.

Some Basics about Computer for Starters

Computer

Personal Computer

      A computer is a programmable machine that receives input, stores and manipulates data , and provides output in a useful format.In other words a computer is a digital electronic alpha-numeric data processing machine in which we can input data, the computer will process it and give us an output.

Digital
  Computers are digital machines because they can only read information as two signals-on or off. These are called digital signals and tightly related to the binary numbers 1 and 0. Any data inside a computer is in the form of combinations of 1s and 0s and will be converted to on and off signals respectively for the devices to identify it. This method of computation, also known as the binary system.

Data
The term data refers to groups of information or a collection of numbers, characters, images or other outputs from devices that collect information to convert physical quantities into symbols, that are unprocessed.

Continued...

Windows XP Commands and Usage

ASSOC      Displays or modifies file extension associations.
AT       Schedules commands and programs to run on a computer.
ATTRIB     Displays or changes file attributes.
BREAK      Sets or clears extended CTRL+C checking.
CACLS     Displays or modifies access control lists (ACLs) of files.
CALL      Calls one batch program from another.
CD       Displays the name of or changes the current directory.
CHCP        Displays or sets the active code page number.
CHDIR     Displays the name of or changes the current directory.
CHKDSK     Checks a disk and displays a status report.
CHKNTFS     Displays or modifies the checking of disk at boot time.
CLS      Clears the screen.
CMD      Starts a new instance of the Windows command interpreter.
COLOR     Sets the default console foreground and background colors.
COMP      Compares the contents of two files or sets of files.
COMPACT     Displays or alters the compression of files on NTFS partitions.
CONVERT     Converts FAT volumes to NTFS.  You cannot convert the
         current drive.
COPY     Copies one or more files to another location.
DATE     Displays or sets the date.
DEL       Deletes one or more files.
DIR       Displays a list of files and subdirectories in a directory.
DISKCOMP     Compares the contents of two floppy disks.
DISKCOPY      Copies the contents of one floppy disk to another.
DOSKEY      Edits command lines, recalls Windows commands, and creates macros.
ECHO       Displays messages, or turns command echoing on or off.
ENDLOCAL     Ends localization of environment changes in a batch file.
ERASE      Deletes one or more files.
EXIT      Quits the CMD.EXE program (command interpreter).
FC       Compares two files or sets of files, and displays the differences
         between them.
FIND     Searches for a text string in a file or files.
FINDSTR     Searches for strings in files.
FOR      Runs a specified command for each file in a set of files.
FORMAT     Formats a disk for use with Windows.
FTYPE      Displays or modifies file types used in file extension associations.
GOTO      Directs the Windows command interpreter to a labeled line in a
         batch program.
GRAFTABL    Enables Windows to display an extended character set in graphics
         mode.
HELP      Provides Help information for Windows commands.
IF        Performs conditional processing in batch programs.
LABEL    Creates, changes, or deletes the volume label of a disk.
MD       Creates a directory.
MKDIR    Creates a directory.
MODE     Configures a system device.
MORE     Displays output one screen at a time.
MOVE     Moves one or more files from one directory to another directory.
PATH       Displays or sets a search path for executable files.
PAUSE    Suspends processing of a batch file and displays a message.
POPD     Restores the previous value of the current directory saved by PUSHD.
PRINT    Prints a text file.
PROMPT   Changes the Windows command prompt.
PUSHD    Saves the current directory then changes it.
RD       Removes a directory.
RECOVER     Recovers readable information from a bad or defective disk.
REM      Records comments (remarks) in batch files or CONFIG.SYS.
REN      Renames a file or files.
RENAME     Renames a file or files.
REPLACE    Replaces files.
RMDIR      Removes a directory.
SET         Displays, sets, or removes Windows environment variables.
SETLOCAL    Begins localization of environment changes in a batch file.
SHIFT      Shifts the position of replaceable parameters in batch files.
SORT       Sorts input.
START    Starts a separate window to run a specified program or command.
SUBST    Associates a path with a drive letter.
TIME     Displays or sets the system time.
TITLE    Sets the window title for a CMD.EXE session.
TREE     Graphically displays the directory structure of a drive or path.
TYPE      Displays the contents of a text file.
VER       Displays the Windows version.
VERIFY     Tells Windows whether to verify that your files are written
         correctly to a disk.
VOL      Displays a disk volume label and serial number.
XCOPY     Copies files and directory trees.

Something About Torrents

Torrents :

Torrent is a small file (around few kilobytes) with the suffix .torrent, which contains all the information needed to download a file the torrent was made for. That means it contains file names, their sizes, where to download from and so on. You can get torrents for almost anything on lots of web sites and torrent search engines(For Eg: torrentz.com).

Torrent is the most popular way of downloading large files, including movies and games (remember legality of downloading). Anyway, to download anything through a torrent you need a torrent client, which is a small software that you need to install on your computer(Eg: BitTorrent). The original BitTorrent client was written in Python and it has been made open-source. Thanks to that, we have a large variety of torrent clients today. Just choose which one you like.

Downloading with a torrent is advantageous especially when downloading files which are momentarily very popular and which lots of people are downloading.Because the torrent is different from the typical method of downloading files from a centralized computer(called server) to our computer(called client). Instead, torrent downloads proceeds using different computers(called peers) on the Internet which holds different pieces of the original file. Servers called trackers will connect our computer to these peers and start downloading pieces of the original file from the peers simultaneously(if possible). This will increase the downloading speed rather than downloading from a single server. Also remember that after we download some part of the file we too is a peer and start sharing our part to others.That is when more people download the file, the higher speed for everyone.

Top Rated Torrent Search Engines

• Mininova
• Isohunt
• Picktorrent
• Torrentz

Top Rated Torrent Client Softwares

• uTorrent 
• Vuze (Azureus)
• BitTornado
• BitTorrent
• BitComet