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Showing posts from 2008

How to solve Browser Hijacker Problem ?

Here's a series of steps by step on how you can take to use Hijack This to remove a browser hijack. So Before you start please Download and install Hijack This STEP 1 Use Safety Stuff to backup your documents and create a system restore point. STEP 2 Check for suspicious startup items You can use Hijack This to clean out hijacked items from Microsoft's Internet Explorer (redirections due to spyware), however they will return if the executable program causing it is not removed. a.Click on Start> Run and type " msconfig " and click OK. b. Select the "Startup" tab. c. Uncheck any items you don't recognize. Note that many legitimate programs will appear here too.Most spyware will load from this area. If unsure if a particular item is legitimate or not, do a Google search on the .exe file name that loads. The only caveat here is that some spyware .exe files get a randomly generated name, so a search will not identify them. You can

What is browser hijacker ?

A browser hijacker (sometimes called hijackware ) is a type of malware program that alters your computer's browser settings so that you are redirected to Web sites that you had no intention of visiting. Most browser hijackers alter default home pages and search pages to those of their customers, who pay for that service because of the traffic it generates. More virulent versions often: add bookmarks for pornographic Web sites to the users' own bookmark collection; generate pornographic pop-up windows faster than the user can click them shut; and redirect users to pornographic sites when they inadvertently mistype a URL or enter a URL without the www. preface. Poorly coded browser hijackers -- which, unsurprisingly, are common -- may also slow your computer down and cause browser crashes. Browser hijackers and the pornographic materia l they often leave in their wake can also be responsible for a variety of non-technical problems. Employees have lost jobs because of cont

Types of broadband connection

Digital Subscriber Line (DSL) DSL is a wireline transmission technology that transmits data faster over traditional copper telephone lines already installed to homes and businesses. DSL-based broadband provides transmission speeds ranging from several hundred Kbps to millions of bits per second (Mbps). The availability and speed of your DSL service may depend on the distance from your home or business to the closest telephone company facility.    The following are types of DSL transmission technologies :   Asymmetrical Digital Subscriber Line (ADSL)   – used primarily by residential customers, such as Internet surfers, who receive a lot of data but do not send much. ADSL typically provides faster speed in the downstream direction than the upstream direction. ADSL allows faster downstream data transmission over the same line used to provide voice service, without disrupting regular telephone calls on that line.    Symmetrical Digital Subscriber Line (SDSL)  – used typically by businesse

What is broadband?

What is broadband? The term broadband commonly refers to high-speed Internet access. The FCC defines broadband service as data transmission speeds exceeding 200 kilobits per second (Kbps), or 200,000 bits per second, in at least one direction: downstream (from the Internet to the user’s computer) or upstream (from the user’s computer to the Internet). How is broadband different from DIAL-UP service? - Broadband service provides higher speed of data transmission—Allows more content to be carried through the transmission “pipeline.”Broadband provides access to the highest quality Internet services—streaming media, VoIP (Internet phone) , gaming, and interactive services. Many of these current and newly developing services require the transfer of large amounts of data which may not be technically feasible with dial-up service. Therefore, -broadband service may be increasingly necessary to access the full range of services and opportunities that the Internet can offer. -Broadband is

Introducing to JavaScript (2)

It's important to understand the difference between Java and JavaScript .   Java is a full programming language developed by Sun Microsystems with formal structures, etc. JavaScript is a scripting language developed by Netscape that is used to modify web pages. Most JavaScript must be written in the HTML document between tags.You open with a tag, write your JavaScript, and write a closing tag. Sometimes, as an attribute to script, you may add “ Language=JavaScript ” because there are other scripting languages as well as JavaScript that can be used in HTML. We’ll go through some examples to demonstrate the syntax of JavaScript. To understand the workings of JavaScript, it is essential to understand a few basic programming concepts. JavaScript is object-oriented. An Object in JavaScript is a resource that has specific characteristics known as properties and provides several services known as methods and events . An example of an object is document , which represents t

Introduction to JavaScript (1)

Equipment / software We will use Notepad on Windows 98 PCs, but any test editor capable of saving documents in plain-text format will work. Any web browser can be used; we will use Netscape Navigator. Be aware, however, that there are some browsers that would handle your code differently. Handouts & class files Class handout: Introduction to JavaScript base.html cat.html demo.html dog.gif family.gif hamster.gif harry.gif logoscroll.gif logostill.gif resources.html Prerequisites We will assume you have a working knowledge of HTML tags. Introduction In this class, you'll become familiar with some concepts and terminology of JavaScript by creating some working examples. We hope you’ll learn enough that you are able to use the materials referenced at the end of this handout on your own. This course will NOT be dealing with programming fundamentals, or rigorous programming struct

What is Virtual Worlds ?

Virtual Worlds - Computer games date back to the early days of computing research. The creation of the Internet allowed game players to interact with each other. Multiuser dungeons (MUD) and multiuser shared hallucinations (MUSHs) are two types of gaming environments. Some of these programs use object-oriented programming techniques called MOOs. There are two types of Virtual World: text-based and GUI-based virtual world. Collaboration - Working with other users connected to a server. You can conduct online meetings. Allows you to share documents with others in real time. Microsoft’s NetMeeting allows collaboration.

What is Instant Messaging (IM) ?

Instant Messaging (IM) - Real-time communications service that notifies a user when people are online and then allows the user to exchange messages or files with them or join a private chat room. Many IM services also can alert you to information such as calendar appointments, weather, stock quotes or sport scores. How does it work? 1. Login to the IM server 2. server checks if any established friends, family or co-workers, called buddies are online. 3. Send instant messages to online buddy 4. instant message travels through messaging server and then to online buddy

What is Message Board ? What is Chat ?

Message Board - A popular web-based type of discussion group that does not require a newsreader. It is also called a Discussion board . Chat - A general term for real-time communication on the Internet or Web. Private chat – occurs between two individuals. Public chat – group chat area. Lurking – the practice of reading messages and not contributing to the discussion. Chat rooms – Web chat sites that use the browser client software interface to create combined text and graphic environments for chat participants. Emoticons (or smileys) are used to display humor and emotions in their messages. Netiquette – Internet etiquette suck as avoid flaming and spamming. Types of chat rooms: Voice chats, Video chats, Radio chats. Internet Relay Chat (IRC) - In 1988, developed as a multiuser program at the University of Oulu in Finland. IRC uses a client-server network model. IRC servers are connected through the Internet to form an IRC network. Original network was EFNet, wh

What is Newsgroups ?

Newsgroups - Area on the Web where users conduct written discussions about a particular subject. Also called threaded discussion. The topic categories originally were called newsgroups or forums . Usenet categories are also referred to as Internet discussion groups. Usenet was one of the first large distributed information databases in the world. A distributed database is stored in multiple physical locations, with portions of the database replicated in different locations. Newsgroups stores messages on an electronic bulletin board as articles or postings that are sorted by topic. A series of postings on a particular issue is called a thread. Usenet is a network of computers called news servers . Periodically news servers connect to each other and compare a list of articles that each currently is storing. After this comparison, each news server obtains copies of the articles it does not have. This store-and-forward process is called obtaining a newsfeed . Each news server site em

Mailing List

Mailing List - A list of names and e-mail addresses for a group of people who share a common interest in a subject or topic and exchange information by subscribing to the list. A popular way of sharing information is to join, or subscribe to, a mailing list. Information is sent to the mailing list through e-mail by posting a message to the list. Different types of e-mail software – LISTSERV, ListProc, and Majordomo. A list server runs the e-mail list software. In commercial mailing lists, advertisers send promotional materials for specific products to customers based on their expressed preferences. A list moderator moderates a mailing list to ensure that the list always receives and sends appropriate and relevant information to its members. When an individual does not moderate the list and postings are sent to list members automatically, the list is an unmoderated list . A closed list is one in which membership is not automatic. A list administrator oversees one or more maili

Electronic Mails (E-mail)

Electronic Mails (E-mail) - One of the most popular forms of business communication. Fast and inexpensive. Sent and received at any time. How does it work? 1. Create and send message 2. Your software contacts ISP mail server. 3. Mail server determines best route 4. Mail server transfers message to PO3 server. 5. When e-mail software checks for e-mail messages, message transfers from POP3 server to recipient’s computer • SMTP (Simple Mail Transfer Protocol): decides which paths your e-mail message takes. • POP (Post Office Protocol): handles incoming messages. • IMAP (Internet Message Access Protocol): used to retrieve messages from a server. • MIME (Multipurpose Internet Mail Extensions): specifies how to encode nontext data. The destination mail server’s software handles the details of distributing the message locally. The mail server holds the new message, until the recipient’s computer requests the message. Mail client software, or an e-mail program, requests the ma

Network Communications Technologies

Network Communications Technologies - Specific combinations of hardware and software that allow different devices on several types of networks to communicate. • Ethernet , the most popular LAN, is based on a bus topology, but can be wired in a star pattern. This LAN technology enables personal computers to contend for access to the network. Variations of the Ethernet standard include Fast Ethernet and Gigabit Ethernet. • Token ring controls access to the network by requiring that network devices share or pass a token or special signal to access the network. • Internet transmissions commonly use transmission control protocol/Internet protocol, or TCP/IP , to manage data transmission by breaking it up into packets. The 802.11 specification is used for wireless LANs. • The Wireless Application Protocol (WAP) uses a client/server network and allows wireless mobile devices to access the Internet and its services such as the Web and e-mail.

Network Topology

Network Topology - Configuration or physical arrangement of devices in a communications network. Networks usually use combinations of three topologies. Topology 1. Bus Network - Consists of a single central cable, to which all computers and other devices connect. Bus is physical cable or backbone. Inexpensive and easy to install. 2. Ring Network - Cable forms closed ring, or loop, with all computers and devices arranged along ring. Data travels from device to device around entire ring, in one direction. 3.Star Network - All devices connect to a central computer, called the hub. All data transferred from one computer to another passes through hub.

Networks

Networks • A collection of computers and devices connected by communications channels that facilitates communications among users and allows users to share resources with other users.Sharing resources include data & information , software and communication. •A network interface card is used to connect a computer to a network of other computers. A server is any computer that accepts requests from other computers that are connected to it and shares some or all of its resources, such as printers, files, or programs, with those computers. Connecting computers this way is called a client/server network.  •The server runs software that coordinates the information flow among other computer called clients. Network operating system is the software that runs on the server. • A network that works over a relatively short distance (no more than a few thousand feet ) is called a local area network (LAN) . Wide area network -  Network that covers large geographic area. Internet is wo

Wireless Transmission Media

Wireless Transmission Media - send communications signals through air or space. Used when inconvenient, impractical, or impossible to install cables. Types Wireless Transmission Media 1. Broadcast Radio – distributes radio signals through the air over long distances such as between cities, regions and countries and short distances such as within am office or home. Transfer rate = up to 54 Mbps *BluetoothTM – uses short-range radio waves to transmit data at a rate of 1 Mbps among BluetoothTM-enabled devices. To communicate between each other a small chip is embedded in the devices. BluetoothTM enabled devices include desktop PC, notebook PC, hand-held computers, Internet appliances, cellular telephones, fax machines and printers. 2. Cellular Radio – a form of broadcast radio that is used widely for mobile communications, specifically wireless modems and cellular telephones. Transfer rate = 9,600 bps to 384 Kbps *Personal Communication Sevices (PCS) is asset of technologi

What is Physical Transmission Media ?

Physical Transmission Media - Wire, cable, and other tangible (touchable) materials used to send communications signals. Type 1. Twisted pair cable - consists of one or more twisted pair wires bundles together. Each cable has two separate copper wires that are twisted together. These wires are twisted together to reduce noise. * Noise – an electrical disturbance that can degrade communication. 2. Coaxial cable - usually referred as coax, consists of a single copper wire surrounded by at least three layers : (a) insulating material (b) a woven or braided metal (c) a plastic outer coating Cable TV wiring usually uses coaxial cable because it can be cabled over longer distances than twisted pair cable. 3. Fiber-optic Cable – consists of dozens or hundreds of thin strands of glass or plastic that use light to transmit signals. Each strand called an optical fiber is as thin as a human hair. Inside the fiber -optic cable, an insulating glass cladding and a protective c

What is Computer Communications ?

Computer Communications - Describes a process in which one computer transfers data, instructions and information to another computer(s). Some devices that can serve as sending and receiving devices in a communication system are: (a) personal computers (b) notebook computers (c) Web-enabled cellular telephones (d) Web-enabled handheld computers (e) WebTV™ (f) GPS receivers The primary function of a communications device such as a modem is to convert or format signals so they are suitable for the communications channel or a receiving device. When using a telephone line as the communication channel, you need to convert between analog and digital signals. An analog signal consists of a continuous electrical wave. Computers however, process data as digital signals. A digital signal consists of individual electrical pulses that represent the bits grouped together as bytes. Circuit Switching vs Packet-Switching • Circuit switching – centrally controlled, single-connection me

What is World Wide Web (WWW) ?

World Wide Web (WWW) -A subset of the computers on the Internet that are connected to each other in a specific way that makes those computers and their contents easily accessible to all computers in that subset. A worldwide collection of electronic documents called Web page that contain text, graphics, sound, video, and links to other Web pages. A Web site is a collection of related Web pages. A home page is the starting page for a browser. It is also called the Index page. It provides information about the web site’s purpose and content. A Web browser is software that lets users read HTML documents and move one HTML document to another. A graphical user interface (GUI) is a way of presenting program output using pictures, icons, and other graphical elements instead of just displaying text. The GUI interface presented in Web browsers has been an important element in the rapid growth of the Web. When you use your Internet connection to become part of the Web, your computer bec

Introduction to the Internet & World Wide Web (2)

Ways to access the Internet Internet Service Providers (ISP) – a business that has a permanent Internet connection and offers temporary internet connections to individuals and companies free or for a fee. 1. Regional ISP – ISP that provides access to the Internet through one or more telephone numbers local to a specific  geographic area. 2. National ISP – Type of ISP that provides access to the Internet through local telephone numbers in major cities and towns nationwide and usually offer more services and generally have a larger technical support staff than regional ISPs. 3. Online Service providers (OSP) – Business that provides access to the Internet, as well as members-only features that offer a variety of special content and services. 4. Wireless Service provider (WSP) – Company that provides wireless internet access to users with wireless modems or web- enabled handheld computers or devices. How Data travels the Internet Using a telephone Line Connection 1. You i

Introduction to the Internet & World Wide Web (1)

What is Internet? Sometimes called “the Net”- is a worldwide system of computer networks. The Internet is connecting computers across almost all countries around the world. It enables you to require a file or document from elsewhere in the world virtually The best Virtual Learning, information highway. History of the Internet In the early 1960s, the U.S. Department of Defense (DOD) began a research project authorized as a part of national security. The Defense Advanced Research Projects Agency (DARPA) began examining ways to connect all large mainframe computers to each other and to weapons installations that were distributed all over the world. In 1969, DARPA connected the first computer switches at the University of California at Los Angeles, SRI International, the University of California at Santa Barbara and the University of Utah. This experimental WAN, called the ARPANET, grew over the next three years to include over 20 computers. ARPANET uses the Network Control Protoc

What is Information Security ?

Information security means protecting information and information systems from unauthorized access, use, disclosure, disruption, modification, or destruction. Information Security is a well-informed sense of assurance that the information risks and controls are in balance.-Jim Anderson Inovant (2002) Information Security objective is to protecting the interests of those relying on information, and the system and communications that deliver the information from harm resulting from failures of confidentiality, availability and integrity (CIA).

History of the Computer

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1940 In1940, Samuel Williams and Stibitz complete a calculator which can operate on complex numbers, and give it the imaginative name of the Complex Number Calculator (CNC) later we call it Model I Relay Calculator. Stibitz stunned the group by performing calculations remotely on the CNC that located in New York, he used a telephone lines to connect. This telephone can switch parts for logic: 450 relays and 10 crossbar switches. Numbers are represented in "plus 3 BCD"; that is, for each decimal digit, 0 is represented by binary 0011, 1 by 0100, and so on up to 1100 for 9; this scheme requires fewer relays than straight BCD. Rather than requiring users to come to the machine to use it, the calculator is provided with three remote keyboards, at various places in the building, in the form of teletypes. Only one can be used at a time, and the output is automatically displayed on the same one. 1941 Konrad Zuse (German Engineer) completed the Z3.Z3 is the first o

Processors

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The first Pentium until the current state Pentium ("Classic") *Bus width 64 bits *System bus speed 60 or 66 MHz *Address bus 32 bits *Addressable Memory 4 GB *Virtual Memory 64 TB *Superscalar architecture brought 5X the performance of the 33 MHz 486DX processor *Runs on 5 volts *Used in desktops *16 KB of L1 cache *P5 - 0.8 μm process technology    o Introduced March 22, 1993    o Number of transistors 3.1 million    o Socket 4 273 pin PGA processor package    o Package dimensions 2.16" x 2.16"    o Family 5 model 1    o Variants       - 60 MHz with 100 MIPS (70.4 SPECint92, 55.1 SPECfp92 on Xpress 256 KB L2)       - 66 MHz with 112 MIPS (77.9 SPECint92, 63.6 SPECfp92 on Xpress 256 KB L2) * P54 - 0.6 μm process technology     o Socket 7 296/321 pin PGA package     o Number of transistors 3.2 million     o Variants        - 75 MHz Introduced October 10, 1994        - 90 MHz Introduced March 7, 1994        - 100 MHz Introduced March 7, 19