Build Your Own PC: Introduction

Introduction to building a desktop PC

This article deals with building a desktop PC. Relevant information concerning the various components is provided, but detailed information on those components is provided in articles devoted to them on this website under the Hardware menu at the top of each page.

The main components are the motherboard, PC case, power supply unit (PSU), processor, RAM memory, hard disk drive and/or SSD drive, video/graphics card(s) – a PC can have as many graphics cards installed as it has adapter-card slots for them and monitors to connect them to – sound card, optical DVD or Blu-ray drive, monitor(s), keyboard and mouse.

POSTUpgrade your old computer with a motherboard, processor, CPU cooler, RAM memory bundle

Computer hardware troubleshooting flowcharts

As you can see from looking at any of the diagnostic charts made available from the following link, there are no photo-illustrations or explanations of basic computer functions. The intended audience is the hobbyist or technician who already has some experience of repairing computers.

If you can understand a particular flowchart, it would be a good idea to print them just in case you can’t boot your computer and you need the information.

Example flowchart: Video Card Diagnostics –

There are other flowcharts covering the motherboard, disk drives, etc., and laptop repairs.

Information on the components and software installed in a computer

If you need information on what is installed on a computer, the Belarc Advisor from is a free tool (look under Free Download on its website) that identifies a Windows computer’s hardware (motherboard, graphics card, hard disk drive(s), DVD drive, etc.) and software (version of Windows, applications, etc.) and even software licences, including the Windows Product Key that is always required when reinstalling Windows.

It is not yet feasible to build a laptop PC, because you can’t buy all of the parts to assemble one. However, it has been possible to build your own desktop PC for many years. In fact, with a little knowledge, it is possible to do all of the repairs to a desktop PC yourself. If you can build a PC, you’ll know how to repair a hardware failure, because the same knowledge of the components is involved. That is currently not the case if a laptop PC’s hardware fails, because, being built like a Swiss watch, it has to be repaired by experienced technicians provided by its manufacturer or by a third-party company.

This motherboard was accidentally killed by its owner

The person who wrote the following on a computer forum probably killed the motherboard.

“I just built a new computer and everything was working great. I decided to reroute some cables for better airflow. I unplugged the 24-pin power cable from the power supply (PSU) to the motherboard, rerouted the cable and plugged it back in. This was with the PSU still plugged into the wall. I noticed that when I did this, my computer flashed on for half a second, the fans and everything turned on briefly and then turned back off. I didn’t think too much of it until I tried turning on my computer again and realised that it wasn’t working. Nothing will turn on (no fans, lights, hard drives, etc).”

Having read this article, if you are unsure about how to do anything…

Having read this article, if you are unsure about how to do anything, clear the confusion before you attempt to do anything by searching for the information you require on this or other websites, or ask for advice in relevant computer forums (web search: computer forums). Don’t be afraid of being flamed by the members for being stupid, because they know what it was like to be a newbie themselves. Many Internet Service Providers (ISPs) provide access to good forums that include computer and technology forums.

If you are using the information on this section of this website to upgrade a computer, as a precaution, before you make any changes to the hardware or software on the computer, make sure that you have created a restorable backup or system image of the system (or, at the very least make copies of the data files if you have the program installation disks) in order to be able to return your system to the state it was in before an irrecoverable crash took place.

The Backups, System Images and Cloud Storage Services section of this website deals with the various methods of creating backups

Before touching electronic components always discharge yourself of static electricity

Before touching electronic components, you should discharge any static electricity by touching the computer’s case while the computer, which is switched off, is plugged into the mains outlet, which is also switched off. The cable and plug have an earth wire that discharge static electricity.

Never open the power supply unit (PSU)

Never open the power supply unit (PSU) in the case, or an old-style CRT monitor, which are now not much in use in the UK and most other developed countries. There are no serviceable parts in them. Only properly trained personnel should work on these components. There are high voltages inside a PSU and a CRT monitor that can kill you, even if they are unplugged! Capacitors in them can hold a lethal charge for long after they have been switched off. Flat-panel LCD monitors don’t make use of high voltages, so aren’t dangerous, nevertheless, only qualified technicians should open one up.

The motherboard, processor, power supply unit and monitor

The motherboard you choose will come with all of the cables you need to connect all of the PC’s components that connect to the motherboard. If you don’t want to buy a cooling unit for the processor, buy a retail boxed processor made by AMD or Intel, not an OEM product,only supported by the vendor, not the manufacturer, that doesn’t come in the official packaging.

The processor shouldn’t be less than a dual-core processor that has two identical processing units in a single housing. You can buy dual-core, triple-core, quad-core, hexa-core and octo-core processors that have one, two, three, four, six and eight cores respectively, new or second-hand. It is expected that processors with 16 cores are possible. A quick search of Amazon today (November 25, 2014) showed dual-core, quad-core, hex-core (6-core) and 8-core Intel and AMD processors available. Most of the purchaser reviews on Amazon are reliable and worth reading. Only people who want a to build a PC that does demanding tasks, such as playing the latest games, would need a high-end processor for it. If you use a PC to run office applications and to access the web, a dual-core or quad-core processor is good enough.

If the case you choose comes with a power supply unit (not all of them do), you may have to buy a replacement. Cheap cases come with cheap power supply units that are definitely not desirable, so read the reviews of a case that comes with a power supply unit before you make a purchase.

The monitor you choose will come with the cables it requires. The installation of all of these components is discussed in detail in this article. All of the assembling requires no more than a number 2 Phillips screwdriver. A pair of tweezers are handy to change jumpers or pick up loose screws and a torch is handy for looking into the case. A magnifying glass is a great help if you need to read small writing on the motherboard.

A purchased motherboard comes with an illustrated user manual the provides precise information on what goes where on it, which can also be downloaded from its manufacturer’s website, usually in the PDF format.

Choosing a power supply unit (PSU) for your self-built desktop PC is an important factor that can easily be underdone or overdone, depending on your computing needs. A gaming computer requires much more power than an office computer. A power calculator allows you to enter the components. When all of the components are entered, the calculator tells you the wattage you require, which allows you to choose a power supply that provides that wattage plus some overhead just in case all of the components are being used at the same time. The power calculator should allow for the motherboard’s use of power. A good one to search the web for is the Enermax Power Supply Calculator.

Note that most desktop PCs housed in a standard ATX PC case are fully upgradable, whereas the upgradability of most laptop PCs is currently (January, 2014) limited to the hard disk drive, which may or may not be replaced with an SSD drive, the CD/DVD/Blu-ray drive, the keyboard and the cooling fan(s). Therefore, this section of this site provides information on how to build and maintain a desktop PC.

The most fortunate aspect of computers and computing is probably the fact that today’s latest and greatest expensive PC hardware (and, to a lesser extent, software) will be available at budget prices in a year to eighteen months time, when it still has several years of useful and productive life left in it. Bear this constantly in mind when you’re reading articles on computers, especially articles on how to build your own PC. There is no imperative need to buy the latest components or software…

A good way to read this Build a PC guide is to have a Notepad or WordPad open. You can then copy and paste any text or website links that you want to remember or use later, which you would then save as a .txt file (e.g., BuildPC.txt)…

Buying compatible components for a PC, assembling them correctly, installing an operating system and getting it to run properly is becoming easier all the time as the components become more and more integrated and easy to install.

Next page: Cables, case modding, device drivers, BIOS/UEFI