Lets start :

When you turn on you PC the first thing your computer does is POST (Power-on self-test) which is looking if there are all peripheral devices (basically input and output devices together) or if there is something wrong with them.Once the POST is completed the next thing coming is BIOS (basic output-input system). The primary function of the BIOS is to identify and initialize system component hardware (such as the video display card, hard disk, and floppy disk) and some other hardware devices.Which means BIOS is preparing the mashine into a low capacity state so other software programs can be loaded from devices like hard disk (HDD).This process is known as bootstrapping.

Bootstrapping is done by boot loader which is placed in the 0 sector of hard disk and loads the kernel (kernel is the core of the operating system) from hard disk into the memory (RAM),kernel is located betwen partition and 0 sector of HDD.Like i sad the kernel is the core of hard disk and he is connecting the application software to the hardware of a computer.

And when everithing loads then the user is able to use operating system.Operating system is like a massive aplication which has the connection with hardwares making it more easy for users to interact with their hardweres.

The Basics

Here is what you need to get started:

• Motherboard
• Processor
• RAM
• Graphics Card
• Hard Drive
• DVD/CD Drive
• Sound Card
• Power Supply Unit
• Case
• Keyboard and Mouse
• Monitor

Please keep in mind that some components may not be necessary for your build. For instance, many people simply stick with the onboard sound on their motherboard, scratching the need for a sound card. Likewise, the same can be said for motherboards with built-in graphics. Some people skip out on an optical drive (although this is only recommended for very cheap rigs).

Motherboard

What all the components are plugged in to. This is an area where many people like to skimp, but accessibility and expandability in the motherboard can mean the difference between a fun build and a nightmare. Please make sure all other components are compatible with this part (i.e., it has enough of the right types of ports for your hard drive(s), optical drive(s), and case fan(s), the right socket type and support for your processor, the correct size for your case, has enough of the correct type of ports for your peripherals (e.g. mouse, keyboard, speakers, etc.), the correct slot for your Graphics Card, and support for your RAM). Recommended for most Intel builds are the P35 and X38/X48 motherboards.

If you feel the need for SLI (multiple Nvidia graphics cards), go with either the 680/780 boards, or, if you've got the cash, the 790i Ultra. For AMD builds, most any AM2+ boards should do you fine.

Processor

First of all, make sure that the CPU (processor) you are getting matches the socket type of the motherboard (e.g. LGA 775, AM2, etc.). Also, make sure the chipset of the motherboard supports the CPU. You can check this at the motherboard manufacturer's website. For performance computers, Intel CPUs are currently your best bet. Keep in mind that Gigahertz (Ghz, the speed of the processor) aren't necessarily equal between different models and brands. For example, the 3Ghz Intel Core 2 Duo e8400 is INFINITELY faster than the 3.2 Ghz AMD Athlon 64+ 6400+. Also, if your programs support them, quad cores are the way to go, but seeing as many don't yet, I would stick with a dual core for the time being. If you are on a tight budget, AMD CPUs can be found for less than Intel's, and a single core may suffice for your needs.

RAM

RAM (Random Access Memory) needs to have the same socket type (SDRAM, DDR, DDR2, DDR3) as the motherboard to be compatible. The most common socket type for RAM for new computers is DDR2 (Double Data Rate revision 2). For most builds, DDR2 800 should be quite fast, although if you plan on extreme overclocking, DDR2 1066 may be warranted. The number after DDR2 is the effective operating frequency, in Megahertz (Mhz, 1000 of which equal one Ghz). Most people will use a dual channel setup (installation varies by motherboard), where two sticks of the same type of RAM are put together, effectively doubling performance. The RAM speed is dependent on the slowest stick, though, so this is only recommended if using two identical RAM modules. For EXTREME overclocking, you may want to use DDR3 (which currently comes in speeds between 1333 Mhz and 2000 Mhz), but this is much more expensive, and motherboards supporting this technology are, as of yet, few and far between. 2GB (gigabytes, 1000 megabytes, amount of memory) are more than sufficient for most builds, but if you plan on doing a lot of multitasking, you may want to think about getting 4GB of memory.

Graphics Card(s)

For a gaming computer, the graphics card is, perhaps, the most important part of the build. It is necessary in any computer, but some motherboards come with built in graphics for those who do not use any graphic-intense applications. Please insure that the slot-type (PCI Express x16, AGPx8, etc.) is supported by your motherboard, and that the power supply has the necessary connections (PCIE 6-pin, PCIE 8-pin, etc.). The two main companies here are ATI (owned by AMD) and Nvidia. Currently, Nvidia supplies the very best of the best when it comes to graphics cards, but in some cases, you may prefer an ATI card. If you want to watch blu-ray/HD-DVD movies, you need to ensure that the graphics card supports HDCP to watch it at the full, intended resolution. Two of the newest cards, the Nvidia 9800GX2 and ATI Radeon 3870 X2 have TWO physical cards in them, replicating SLI and Crossfire respectively in a board that does not support SLI/Crossfire. SLI and Crossfire are the names for Nvidia and ATI's multi-graphics card systems respectively. For the most intense graphics, you may wish to pursue one of these two options (in which case you need to make sure your motherboard supports the technology). The top of the line Nvidia single-card graphics card is the 9800GTX (closely trailed by the 8800 Ultra, 8800 GTS G92, and 8800GTX), and ATI's is the Radeon 3870 (closely followed by the 3850).

Hard Drive(s)

The hard drive is the component which stores all of the software on your computer. There are various interface types (IDE, ATA, SATA, SATAII), of which SATAII is the most recent (and best). This is because it supports the highest bandwidth while sporting the thinnest cable (helping to promote good air flow, and make cable management easier). The most important statistic when buying a hard drive is the storage space. Make sure it has enough (e.g. 200GB, 500GB, 750GB, etc.) storage space for your needs. If you are not sure, see how much you use on you current computer to get a rough estimate. If you still aren't sure, it never hurts (anything but your wallet) to have too much. Performance is mostly dictated by the interface type, spindle speed, and amount of platters. Spindle speed is the speed at which the hard drive rotates. Most desktop hard drives rotate at 7200RPM, although there are faster 10,000RPM drives, but these offer less storage space. That second figure I mentioned, amount of platters, is how many magnetic disks there are within your hard drive. The less there are, the faster, quieter, and less likely to break your hard drive is. The best platter today is available in the Samsung Spinpoint F1 1 TB (terabyte, 1000 gigabytes). It has three platters, each with 333GB of storage space. Most desktop hard drives fit in a 3.5” internal drive bay. Eventually hard drives will be replaced by Solid State Drives (SSDs), but these are currently far too expensive and don't provide nearly enough storage space for the average user.

Optical Drive

Where you put your optical discs (DVD, CD, blu-ray, etc.). There are two main interface types (SATA and IDE), with SATA once again being the preferable type. For most budgets, a DVD writer would be recommended, although none are necessary if you are building an “el cheapo” computer. If you have the money and the media, you may want a blu-ray drive though. The fastest of these write blu-ray discs at 6x, while DVD writers can write at speeds of up to 20x. The claimed speeds are important, but there are more variables than the test figures represent (due to variations in which media brand is used for the testing). The fastest optical drive on the market today (DVD writer) is the Samsung SH-S203B. Most optical drives fit in a 5.25” external drive bay. Another technology some may be interested in is lightscribe, which laser etches an image into the top of a disc, although these drives cost slightly more. Also, for almost everybody, floppy drives are no longer needed.

Sound Card

While almost every motherboard nowadays comes with built-in sound, aftermarket sound cards will always be there for the audiophile. There are varying interface types (PCI, PCI Express x1). The most popular today are the Creative X-Fi Series and the ASUS Xonar D2 series. Some sound cards feature onboard RAM to offload all of the sound processing from the CPU, boosting performance in any application that involves sound (sometimes a few FPS (frames per second) even in intense games). Only get an aftermarket sound card if you truly appreciate rich, vibrant sound and have a good set of speakers/headphones to go fully take advantage of one.

Power Supply Unit

The PSU is what provides power to all of the components of your computer. It is important not to skimp on this, as it is the only component that, should it fail, has the possibility of taking all the other components with it. The most important thing to look for in a PSU is the brand, as certain brands have a reputation for power supplies that will not crash (as some cheap, generic ones have a tendency to do, sometimes with explosive results). Some recommended brands are PC Power & Cooling, Antec, Seasonic, Enermax, Thermaltake, OCZ, Corsair, Thermaltake, Tagan, and Gigabyte. The most important statistic in the PSU is the wattage rating. This tells you how much wattage the PSU can supply to your components. Use a wattage calculator (and add 15% or so for safety's sake) to determine what kind of wattage it will take to run your computer. Also important is the efficiency. Many PSUs today are stamped with the 80plus seal of approval, signifying that they run at 80% or better efficiency (e.g. less than 20% of the supplied power is lost as heat), improving performance, component life, and helping reduce energy consumption. Also, be sure that the PSU has connectors for all of the components you need to power, and try to find one that will allow you to keep it as you add things to your computer. Modular support is a nice feature to have (not all of the wires are permanently attached to the PSU, so the connectors you aren't using can be unplugged from the power supply, reducing cable clutter), but you pay a premium for it.

Case

What you put all of your components in. Important things to look for in the case are it's size, motherboard form factor, if it will hold your graphics card, what kind of bays it has, the provided cooling, and what it looks like. Size-wise, for most people the only way to go is either Mid-Tower ATX or Full Tower ATX (sometimes called Super Tower ATX). Either of these will hold an ATX motherboard, and most Full Tower cases will hold an Extended ATX (EATX) motherboard. Check reviews to see if your graphics card will fit the case, as some of the newer graphics cards are quite long and do not fit in some cases. You need to make sure it has enough 3.5” internal bays for your hard drives, 5.25” external bays for your optical drives, and if it has 3.5” external bays if you use accessories that utilize those bays. Make sure it has adequate cooling for the setup you are planning on building. I recommend that the case you choose has at least a 120mm fan or 2 80mm fans. Any more than that should be good as well. Look to see it h as at least on exhaust fan, and that there are not more fans than you need (this will make it very loud). If you are planning on watercooling, you should definitely go with a Full Tower case, and for ease of installation find out if it fits the radiator you are planning on using. Looks are personal preference, but I find some people like to have a conservative looking case with one solid color and usually either in black, beige or white, while others like flashy cases with side windows, LED fans and crazy paint jobs.

Keyboard and Mouse

Keyboards and mice are generally best chosen after trying out a few and seeing what you like best. There are a few things to look for. If you want an uncluttered desktop, go for a wireless set. If you want all-out gaming performance, try a keyboard with macro keys and the ability to disable the windows key, and a mouse with lots of extra buttons, a “clicky”, or tactile, scroll wheel, and a high and adjustable dpi. If you have many late-night sessions, look for a mouse with an illuminated scroll wheel and a backlit keyboard (such as the Saitek Eclipse II, arguably the best back-lit keyboard to date). But most important, MAKE SURE WHATEVER YOU PICK IS COMFORTABLE!!! I can not stress this enough. You can have the best mouse/keyboard combo ever, but if you find them uncomfortable, you'll find it hell to use your computer.

Monitor

Finally the monitor, what you will be viewing everything you do with. Make sure it is as big as you can afford. A bigger monitor reduces eye-strain and increases the amount of windows you can work with at one time. There is no longer any reason to get a CRT monitor, so be sure to go for an LCD. Also, be sure to get a widescreen (16:10/16:9) as opposed to a fullscreen (4:3), because you get more screen for the price (widescreen panels are cheaper to manufacture). The contrast ratio is quite important to how good the images look. It tells you how black the blacks are and how white the whites are. The higher the better. Make sure is reproduces at least 16.2 million colors, as this means it is 16-bit (8-bit monitors simply can't compete when it comes to visual quality). The response time should be as low as possible, but make sure that the monitors you are comparing measure response time the same way, or else this statistic is pointless (some measure black-to-white-to-black, while others measure grey-to-grey). Other things to look for in a monitor are how much the stand adjusts, how many screen adjustment options there are (as a general rule, the more the better), and how good you think it looks. Just like mice and keyboards, I recommend you try out the monitor you are thinking about purchasing before you do so, as you want to be sure you will be happy with it after you plop down the cash (which can be quite a lot).

Conclusion

Now you should have a good idea of what kind of computer you will be building. It really isn't nearly as hard as it seems at first. This is all stuff I've come across in the two years I've been interested in building computers, and I could have gone into much more depth, but won't in this article for the sake of simplicity. After you've read this and chosen what components you are going to purchase for your build, you just need to put it all together. I will explain how to do that in a future article, but I promise, it is no harder than it was to choose what to buy. I GUARANTEE you will be happy if you build your own computer, as so long as you do a little research before buying the parts, you will end up with a better performing, cheaper computer than Dell and the likes will ever sell you. Good luck, and be sure to check back in the coming weeks for more of my guides!

Three Kinds of Users, Three Kinds of Personal Computers

If you plan to use your computer to run high end graphic design programs, or run cutting edge, 3-D computer games, digital video, or demanding multimedia applications, you are a Power User, and you will want a powerful computer.

If you plan to use your computer mainly to run the popular office and accounting programs, to send and receive e-mail, and to surf the Web; or you are buying your first family computer, which you expect to be used for games, to run educational software, and to get online, then you are more of an Average User. You will want a solid system, but nothing that will run NASA.

If you really don't need a computer to do much more than send and receive e-mails, surf the Web a bit, and run a few undemanding programs now and then, you are what you might call an Occasional User. For these kinds of activities, you can get by with a very basic machine.

Power Users

Demanding users of high end graphics and design programs and cutting edge games will want a computer that includes the following basic components

• 800-plus Mhz processor
• 128MB or more of RAM
• 10GB or larger hard disk drive
• 4.8X DVD-ROM drive
• 250MB zip drive
• 3-D sound card
• Surround sound speaker set
• 19 inch monitor
• 2-D/3-D graphics accelerator card
• 32MB video RAM
• 56.6K V.90 modem

This baby will probably cost you, but you'll never lack for the performance you need.

Average User

Most people doing most of the things most often done on a computer will be very happy with the following basic components

• 500 Mhz processor
• 64MB or more of RAM
• 8B or larger hard disk drive
• 6X DVD-ROM drive
• 3-D sound card
• Stereo speakers
• 17 inch or larger monitor
• 16MB 2-D/3-D graphics accelerator card
• 56.6K V.90 modem

Keep in mind that the hardcore gamers in your family are going to demand more of everything no matter what you bring home.

Occasional Users

Even computer manufacturers are beginning to recognize the importance of computer users who want little more from their machines that Internet access. A whole new generation of “information appliances” has been evolving for a few years now. Occasional users who still want the computer experience will be fine with the following components

• 466 Mhz processor
• 32MB RAM
• 4GB hard disk drive
• 4MB video RAM
• 15 or 17 inch monitor
• 56.6K V.90 modem

This is the computer you might want to get for grandparents who don't care much about computers, but who want to have e-mail and might occasionally surf the Web. But be sure that interest and not age is the determining factor here; I've seen many a computer shy senior take to cyberspace like a duck to water.

Connect To The Internet

Probably the most common reason people buy a personal computer these days is to connect to the internet. I seems as though everyone is getting wired these days. Having an e-mail account is almost as important as having a telephone. Online shopping is sweeping the country (make that the world), and changing retail sales in ways we are only beginning to understand. Online stock trading is a phenomenon with world changing implications. And pretty soon, we will all be voting online.

Business and Personal Finance

A great many people us personal computers to run business or personal finance applications, such as Quicken and MS Money.

Personal computers can take much of the drudgery out of bookkeeping. Beyond simple number crunching, they can improve your accuracy, present date in more meaningful ways, allow you to change numbers and categories with a mouse click, and even help you prepare and file your taxes.

Education

More and more parents are buying personal computers for their children with an eye toward their educational uses. The shelves are fairly creaking with computer programs that help children learn to read, write, and think critically. Computer encyclopedias combine text, sound, and moving pictures to create rich learning resources. More and more schools are teaching with computers. Kids, from grade school to college, go online to find information for their research papers. And chances are, virtually every student in school today will be using a computer after he or she graduates and starts working.

Games

Computer games, of course, draw many people to the personal computer, especially with the advent of online gaming. Most computer gamers are younger, but you'd be surprised how many over 40 gamers there are out there. Some of the more cerebral games, such as historical simulations and puzzle type games, draw almost exclusively from an older audience. One of the industry's true blockbusters, Myst, appealed primarily to older players.

Computer Graphics and Publishing

Artists, both professional and amateur, are turning to computers, for a new form of self expression. Universities offer classes in computer related art courses. The graphic design industry is positively dependent on computers, as are book and magazine publishers. And the artistically challenged are turning to graphic design and publishing programs to add color and design to their church and school newsletters, holiday letters, and personal Web pages.

Digital Photography

The proliferation of digital cameras has created yet another reason to own a personal computer. A digital camera stores the pictures you take in computer files inside the camera's hard disk or special memory cards. These files can then be transferred to a personal computer, where they can be stores and organized for easy access, and printed out later on special paper. Digital pictures are also easy to send across the internet to far friends and family.

Norton Anti-Virus. This antivirus is good in the fact that it does the job and u won't have anything go undetected as such. There is a few downsides to this program, 1 its cost yearly, and 2 it slows down the computer dramatically. There is a free trial that goes for about a month but it doesn't allow u to do much. This program also comes in the form of toolbar in your internet browser. Norton is the basic program, which new computers usually comes with a trial version or top dollar computers will have full version for say a year, on most windows computers.

AVG anti-virus, spyware, root kit. This program has a free edition anti-virus and root kit which last forever. AVG anti-virus updates regularly, usually each day with new protection against new viruses. There is also a virus dictionary included in the program which has all information on the virus. The program also keeps the infected files in a vault for future reference. You can clean out this vault. AVG also gives you as soon as it finds a problem, to be able to heal, move to vault and cancel options for fast and effective solutions. AVG also has a root kit to download, which goes deep into the computers and gets anything undetected by anti-virus, or in other words files that seemed safe to the anti-virus which in fact isn't. Also looks through the hidden files. Spyware is not free but when you have this program it blocks off spyware before they hit your computer. Even if the file has been there, it will detect it. There is a buy version of the anti-virus which has lots more features. I do believe AVG
Does a great job, and is ideal for people who want easy to use and understanding anti virus, free version that does a great job, and updates regularly. AVG is very popular amongst computer shops, and repair it places.

SpyBot, Spybot is a good user friendly spyware software available for free. This program lets u know of anything that's about to change and give u the option the block it, or ignore it. This program has a downside and it can think your firewall is a spyware, and can turn it off, but if such a thing happens just uninstall it and install it again. Also make sure your firewall is turned on. If not, turn it on and accept the change when it pops up. One really annoying thing, even though it does a great job, I remember once I had a key logger nothing could find but this did, it just in the way and does slow down the computer a little. The pop up things don't disappear for a while, even though you clicked it so you will have to be patient with this one..

Windows Live One Care. A necessity when using MSN and HOTMAIL. this searches/scans incoming files from emails or msn messenger. This is to ensure optimal safety from people when they send u things. Although you can't use anything else, what u can do when using MSN messenger is disable the virus check when receiving files from other contact members and scan with another virus protection e.g. AVG. this takes no time at all. Usually it takes a very long time. First it logs onto their website and checks which is a slow process. When hotmail uses it, it's mainly for checking the files you updated but if u get sent one, it gives you a notice to say it may have a virus, giving you the option to scan.

Google, Yahoo, and other toolbars. Toolbars are most essential when coming to pop ups. this happens when surfing the net and a pop up comes, its blocks the pop up, meaning no viruses from pop ups. Also it protects u from other viruses from the sites as you browse them. You can also turn bits off and on to how it suits you. There is also a downside to toolbars. One thing is they take up so much room at some points half your view area is taken up. So why use them if u can't see what you looking up. Personally I would just leave the normal antivirus do the job. Yes they are good to the point that they are programmed differently from other anti viruses and may see the viruses other virus protections might not see. It may be in their programming to have different definitions to what a virus is. They can pick up things some other things can't.

Well I do hope this info did help you out. I have shown you how 3 different viruses are different and their good and bad points. Shown some toolbar virus protectors. Spyware is a big factor that needs to be seen into. Spyware includes key logging, which is when implanted into your computer; people can see everything you type, meaning your usernames and passwords on the site you visit, credit card details. All viruses are different so try to find one that fits for you and always, always get to know the virus protection you use, very well.