Showing posts with label Computers-Basics. Show all posts
Showing posts with label Computers-Basics. Show all posts

How to Maintain pc

The internet is flooded with tips and advice on PC cleaning.
Much of this advice urges you to buy useless programs that
cost hundreds of [insert your currency here.] Look no further:
you can follow this guide and get your PC clean without
spending any money whatsoever. I do recommend programs,
which have  paid upgrades; however, I am confident these
programs,  when upgraded,  are  worth every penny and
hundreds of Windows Guides readers. 
agree with me.

Let’s get right into things; to clean and maintain your PC:
1.  Find and remove malware.
2.  Uninstall unnecessary programs.
3.  Delete junk/temporary files.
4.  Optimize your system.
5.  Defragment your hard drive.
6.  Backup your data.
By following these steps, you’ll ensure your computer is
performing at its best and is error free.
Because this book is designed for beginners, instructions on

manually tweaking your PC are not included.

AVG Internet Security
I’ve used AVG for many years on my computers because I trust
it and it has always protected my files from malicious .

AVG helps you stay safe while you shop, bank online,
watch videos, search or surf the web, download
music, documents and pictures, and email or chat.
Every document or file you download, every web page or
link you click on, is scanned by AVG before you open it.
Unlike other security products, we stop the threats
before they reach your hard drive and become a
problem. Safe internet surfing is now possible.


Protection against viruses is great but prevention is even better
and ESET constantly update their virus definitions to ensure
that the even the newest viruses are well protected against.
Virus updates do not consume unnecessary system resources
and do not fail–other antivirus programs I have used have
issues with updating and sometimes need a manual fix.

Malware – The generic term used for all forms of software
designed with malicious intent. Viruses, worms, spyware etc.
are all forms of malware. The term virus is often used when
malware should really be used as it describes all forms of
malicious software.
Spyware  –  Spyware tracks a user’s activity by monitoring
browsing habits and key board activity and can even take
screenshots while you use your PC. This information is sent
back to the creator or beneficiary of the spyware. Signs of
spyware include: modified browser homepages, slow internet,
and suspicious looking sites in place of legitimate sites

What is Web browser?

Software that lets a user view HTML documents and access files and software related to those documents. Originally developed to allow users to view or browse documents on the World Wide Web, Web browsers can blur the distinction between local and remote resources for the user by also providing access to documents on a network, an intranet, or the local hard drive. Web browser software is built on the concept of hyperlinks, which allow users to point and click with a mouse in order to jump from document to document in whatever order they desire. Most Web browsers are also capable of downloading and transferring files, providing access to newsgroups, displaying graphics embedded in the document, playing audio and video files associated with the document, and executing small programs, such as Java applets or ActiveX controls included by programmers in the documents. Helper applications or plug-ins are required by some Web browsers to accomplish one or more of these tasks. Also called: browser.

What is timing attack?

An attack on a cryptographic system that exploits the fact that different cryptographic operations take slightly different amounts of time to process. The attacker exploits these slight time differences by carefully measuring the amount of time required to perform private key operations. Taking these measurements from a vulnerable system can reveal the entire secret key. Cryptographic tokens, network-based cryptosystems, and other applications where attackers can make reasonably accurate timing measurements are potentially at risk from this form of attack.

What is macro assembler?

An assembler that can perform macro substitution and expansion. The programmer can define a macro that consists of several statements and then use the macro name later in the program, thus avoiding having to rewrite the statements. For example, a macro called swap exchanges the values of two variables: After defining swap, the programmer can then insert an instruction such as “swap a, b” in the assembly language program. While assembling, the assembler replaces the instruction with the statements within the macro that swap the values of the variables a and b.

whiat is fuzzy logic?

A form of logic used in some expert systems and other artificial-intelligence applications in which variables can have degrees of truthfulness or falsehood represented by a range of values between 1-true and  0 -false. With fuzzy logic, the outcome of an operation can be expressed as a probability rather than as a certainty. For example, an outcome might be probably true, possibly true, possibly false, or probably false.

fuzzy set :- A set constructed using the principles of fuzzy logic. It is used in artificial intelligence to deal with vague or continuous data that cannot be expressed by conventional set theory. In a fuzzy set, the membership function for the set of objects is not binary but continuous, such that an object may be a member of the set to a specific degree or arbitrary value. In computer programming, a fuzzy set is usually effectively represented by an array.

what is file fragmentation?

The breaking apart of files as they are stored by the operating system into small, separate segments on disk. The condition is a natural consequence of enlarging files and saving them on a crowded disk that no longer contains contiguous blocks of free space large enough to hold them. File fragmentation is not an integrity problem, although it can eventually slow read and write access times if the disk is very full and storage is badly fragmented. Software products are available for redistributing optimizing file storage to reduce fragmentation. 2. In a database, a situation in which records are not stored in their optimal access sequence because of accumulated additions and deletions of records. Most database systems offer or contain utility programs that resequence records to improve efficiency of access and to aggregate free space occupied by deleted records. 

The structure of a file that defines the way it is stored and laid out on the screen or in print. The format can be fairly simple and common, as are files stored as “plain” ASCII text, or it can be quite complex and include various types of control instructions and codes used by programs, printers, and other devices. Examples include RTF -Rich Text Format, DCA -Document Content Architecture, PICT, DIF-Data Interchange Format, DXF -Data Exchange File, TIFF-Tagged Image File Format, and EPSF -Encapsulated PostScript Format. 

What is data management?

The control of data from acquisition and input through processing, output, and storage. In microcomputers, hardware manages data by gathering it, moving it, and following instructions to process it. The operating system manages the hardware and ensures that the parts of the system work in harmony so that data is stored safely and accurately. Application programs manage data by receiving and processing input according to the user’s commands, and sending results to an output device or to disk storage. The user also is responsible for data management by acquiring data, labeling and organizing disks, backing up data, archiving files, and removing unneeded material from the hard disk.

HTTP status codes

Three-digit codes sent by an HTTP server that indicate the results of a request for data. Codes beginning with 1 respond to requests that the client may not have finished sending; with 2, successful requests; with 3, further action that the client must take; with 4, requests that failed because of client error; and with 5, requests that failed because of server error.
400, 401, 402, 403, 404, HTTP

.NET Framework

A platform for building, deploying, and running XML Web services and applications. It provides a highly productive, standards-based, multilanguage environment for integrating existing investments with next generation applications and services, as well as the agility to solve the challenges of deployment and operation of Internet-scale applications. The .NET Framework consists of three main parts: the common language runtime, a hierarchical set of unified class libraries, and a componentized version of ASP called ASP.NET. See also ASP.NET, common language runtime, .NET Framework class library. 

NET Framework class library  
 A Common Language Specification (CLS)–compliant library of classes, interfaces, and value types that are included in the Microsoft .NET Framework SDK. This library provides access to system functionality and is designed to be the foundation on which .NET Framework applications, components, and controls are built.

.NET Framework data provider :- A component of ADO.NET that provides access to data from a relational data source. A .NET Framework data provider contains classes to connect to a data source, execute commands at the data source, and return query results from the data source, including the ability to execute commands within transactions. A .NET Framework data provider also contains classes to populate a DataSet with results from a data source and propagate changes in a DataSet back to the data source.

What is GPS receiver?

A device that includes an antenna, a radio receiver, and a processor for use with the worldwide GPS -Global Positioning System. A GPS receiver uses position and time information from four GPS satellites to calculate precise information about its current location, its speed of travel, and the current time. A portable GPS receiver may be a stand-alone device or a plug-in unit for use with a portable computer. GPS receivers are used for scientific work, such as surveying, mapping, and studies of volcanoes, as well as for land, sea, and air navigation. On the consumer front, they are used in outdoor activities such as hiking and sailing and in cars to provide location, destination, and traffic information.

What is ini file?

ini file:-Short for initialization file, a text file containing information about the initial configuration of Windows and Windows-based applications, such as default settings for fonts, margins, and line spacing. Two ini files, win.ini and system.ini, are required to run the Windows operating system through version 3.1. In later versions of Windows, ini files are replaced by a database known as the registry. In addition to Windows itself, many older applications create their own ini files. Because they are composed only of text, ini files can be edited in any text editor or word processor to change information about the application or user preferences. All initialization files bear the extension .ini. 

MS-DOS and Windows 3.x, the file extension that identifies an initialization file, which contains user preferences and startup information about an application program

what is three-tier client/server?

A client/server architecture in which software systems are structured into three tiers or layers: the user interface layer, the business logic layer, and the database layer. Layers may have one or more components. For example, there can be one or more user interfaces in the top tier, each user interface may communicate with more than one application in the middle tier at the same time, and the applications in the middle tier may use more than one database at a time. Components in a tier may run on a computer that is separate from the other tiers, communicating with the other components over a network.

Whst is Password Authentication Protocol

Acronym for Password Authentication Protocol. A method for verifying the identity of a user attempting to log on to a Point-to-Point Protocol (PPP) server. PAP is used if a more rigorous method, such as the Challenge Handshake Authentication Protocol (CHAP), is not available or if the user name and password that the user submitted to PAP must be sent to another program without encryption. 2. Acronym for Printer Access Protocol. The protocol in AppleTalk networks that governs communication between computers and printers.

what is X Series for Network Communications

A set of recommendations adopted by the International Telecommunication Union Telecommunication Standardization Sector ITU-T, formerly the CCITT, and International Organization for Standardization ISO for standardizing equipment and protocols used in both public access and private computer networks.
Recommendation Number What It Covers
X.25 Interface required to connect a computer to a packet-switched network such as the Internet
X.75 Protocols for connecting two public data networks
X.200 Seven-layer set of protocols known as the ISO/OSI reference model for standardizing computer-to-computer connections
X.400 Format at the ISO/OSI application layer for e-mail messages over various network transports, including Ethernet, X.25, and TCP/IP. Gateways must be used to translate e-mail messages between the X.400 and Internet ­formats
X.445 Asynchronous Protocol Specification, which governs the transmission of X.400 messages over dial-up telephone lines
X.500 Protocols for client/server systems that maintain and access directories of users and resources in X.400 form
X.509 Digital certificates

What is MIME?

Acronym for Multipurpose Internet Mail Extensions. A protocol widely used on the Internet that extends the SMTP Simple Mail Transfer Protocol to permit data, such as video, sound, and binary files, to be transmitted by Internet e-mail without having to be translated into ASCII format first. This is accomplished by the use of MIME types, which describe the contents of a document. A MIME-compliant application sending a file, such as some e-mail programs, assigns a MIME type to the file. The receiving application, which must also be MIME-compliant, refers to a standardized list of documents that are organized into MIME types and subtypes to interpret the content of the file. For instance, one MIME type is text, and it has a number of subtypes, including plain and html. A MIME type of text/html refers to a file that contains text written in HTML. MIME is part of HTTP, and both Web browsers and HTTP servers use MIME to interpret e-mail files they send and receive. 

What is memory management?

In operating systems for personal computers, procedures for optimizing the use of RAM (random access memory). These procedures include selectively storing data, monitoring it carefully, and freeing memory when the data is no longer needed. Most current operating systems optimize RAM usage on their own; some older operating systems, such as early versions of MS-DOS, required the use of third-party utilities to optimize RAM usage and necessitated that the user be more knowledgeable about how the operating system and applications used memory. See also memory management unit, RAM. 2. In programming, the process of ensuring that a program releases each chunk of memory when it is no longer needed. In some languages, such as C and C++, the programmer must keep track of memory usage by the program. Java, a newer language, automatically frees any chunk of memory that is not in use. See also C, C++, garbage collection, Java. 

Memory management program :- A program used to store data and programs in system memory, monitor their use, and reassign the freed space following their execution. 2. A program that uses hard disk space as an extension of the random access memory RAM.  

Memory management unit :-The hardware that supports the mapping of virtual memory addresses to physical memory addresses. In some systems, such as those based on the 68020, the memory management unit is separate from the processor. In most modern microcomputers, however, the memory management unit is built into the CPU chip. In some systems, the memory management unit provides interfacing between the microprocessor and memory. This type of memory management unit is typically responsible for address multiplexing and, in the case of DRAMs, the refresh cycle. Acronym: MMU. See also physical address, refresh cycle, virtual address.

What is markup language?

A set of codes in a text file that instructs a computer how to format the file on a printer or video display or how to index and link its contents. Examples of markup languages are Hypertext Markup LanguageHTML and Extensible Markup Language XML, which are used in Web pages, and Standard Generalized Markup Language SGML, which is used for typesetting and desktop publishing purposes and in electronic
documents. Markup languages of this sort are designed to enable documents and other files to be platform-independent and highly portable between applications. See also HTML, SGML, XML.

why need For a relational database?

A database or database management system that stores information in tables—rows and columns of data—and conducts searches by using data in specified columns of one table to find additional data in another table. In a relational database, the rows of a table represent records (collections of information about separate items) and the columns represent fields (particular attributes of a record). In conducting searches, a relational database matches information from a field in one table with information in a corresponding field of another table to produce a third table that combines requested data from both tables. 


For example, if one table contains the fields EMPLOYEE-ID, LAST-NAME, FIRST-NAME, and HIRE-DATE, and another contains the fields DEPT, EMPLOYEE-ID, and SALARY, a relational database can match the EMPLOYEE-ID fields in the two tables to find such information as the names of all employees earning a certain salary or the departments of all employees hired after a certain date. In other words, a relational database uses matching values in two tables to relate information in one to information in the other. Microcomputer database products typically are relational databases. Compare flat-file database, inverted-list database.

Os registry?

A central hierarchical database in Windows 9x, Windows CE, Windows NT, and Windows 2000 used to store information necessary to configure the system for one or more users, applications, and hardware devices. The Registry contains information that Windows continually references during operation, such as profiles for each user, the applications installed on the computer and the types of documents each can create, property sheet settings for folders and application icons, what hardware exists on the system, and which ports are being used.

 The Registry replaces most of the text-based .ini files used in Windows 3. x and MS-DOS configuration files, such as AUTOEXEC.BAT and CONFIG.SYS. Although the Registry is common to the several Windows platforms, there are some differences among them. Also called: system registry. See also hierarchical database, .ini, input/output port, property sheet, Registry Editor.

Whai is macro?

In applications, a set of keystrokes and instructions recorded and saved under a short key code or macro name. When the key code is typed or the macro name is used, the program carries out the instructions of the macro. Users can create a macro to save time by replacing an often-used, sometimes lengthy, series of strokes with a shorter version. 2. In programming languages, such as C or assembly language, a name that defines a set of instructions that are substituted for the macro name wherever the name appears in a program a process called macro expansion when the program is compiled or assembled.

 Macros are similar to functions in that they can take arguments and in that they are calls to lengthier sets of instructions. Unlike functions, macros are replaced by the actual instructions they represent when the program is prepared for execution; function instructions are copied into a program only once.