“Get a Personal Trainer for Your Computer!”©

NOTE:  Items highlighted in RED are defined elsewhere in this Glossary, while items highlighted in BLUE are site links for further information.

There are so many YouTube videos and websites that show step-by-step assembly instructions, with graphics and photos, for those who want to build their own computers that I see no need to reinvent them here.  There are links to some of these sites at the end of this discussion.  However, in the interest of completeness (since this is, of course, a site about all things computer), I will summarize the process and provide specific links below...








Not that long ago, assembling a desktop PC meant arranging “dip switches” on the motherboard and on many of the  devices (even the keyboard), finding the correct drivers (many weren’t included with the operating system) and worrying about setting addresses and IRQs.  You really did have to configure the hardware to work with the other hardware as well as the operating system.

Not so much any more.  The evolution of Windowsplug-and-play” has meant that most common software drivers, including those for printers, are pre-loaded in the operating system and don’t have to be located, downloaded and installed separately.  And the motherboards, riser cards, drives and other hardware are pretty much universally compatible without any fine-tuning to get them to work.  If you want to know more about what’s on your motherboard, click on Boards & Chips.  You do have to know how to select your hardware and put it together, but that’s about it.  Don’t let your fear get in the way, look at it as an adventure.  Really.

So why do it?  Pre-built computers can be fine for many people and many purposes.  If you’re just getting your e-mail and surfing the net, almost any current pre-built computer will do, name brand or otherwise.  Add to that some increased video or audio tasks and they may still be acceptable.  But if you have specific business, gaming or graphic tasks in mind, building your own computer might be a superior choice.  A computer is fast only if it’s speedy when it does what you want it to do.  (Click HERE for what makes a computer fast, generally.)  First, you know that you’re getting the best possible hardware in those areas which will be important for your specific type of processing.  Second, you won’t have to worry about the trialware, bloatware, adware and other junk that you usually have to remove from a pre-built computer so that it operates smoothly.  It’s clean and ready to go once you load the operating system, which is another item you can select to meet your specific needs.  Also, because you have personally built the system, you’ll be familiar with it and will be better able to handle any problems down the line if they arise.  [Even if you choose not to, at least you’ll now be familiar with what’s under the hood if you purchase it elsewhere.]  And finally, it’ll cost you less, since you are contributing the labor.  It just takes a little effort.  Therefore, what I discuss below is not so much a how-to manual (for that, I’ve given you some links to those sites, below) as an overview and discussion about what’s involved , so that you can decide if you’re really interested in building your own computer.

Keep this in mind:  The key to building your own computer is detailed planning.  You will find that the most time consuming part of building your own computer is the “planning” stage, discussed immediately below.  The time you spend assembling the hardware and loading the operating system will take a fraction of the time that you spend deciding about your hardware specifications, and then the locating of suppliers and getting all of the necessary parts, cables, tools and the like.  The “garbage in - garbage out” principal is just as relevant here as it is in data entry; if you don’t spend the time up front, you’ll end up with junk when you’re done!

Plan Ahead: Like anything else with computers, you have to give some up front thought to the desired end result before getting started.  That is, what do you want to do with the computer?  Do you want concert-quality audio to listen to music?  Do you want high-speed graphics to watch videos and movies?  Are you going to be number crunching spreadsheets and databases?  Are you going to scan, edit and save lots of photos?  Each of these choices will determine your hardware and software requirements, and the cost, so you can build the computer that will suit your needs.  If you don’t think about what you are going to use the computer for, the result may not be suitable to do those tasks, and you will be very  disappointed.  Check out some of the common pre-built systems and see what they offer for components for the low-end, middle of the road and high-performance systems, which may give you some idea about the necessary components for building your own computer.

Generally, once you’ve come up with your specifications, in order to build your own computer, here’s what you’ll need:

Hardware Selection: First, computer hardware, like most other things in life, comes in varying degrees of quality, usually at various price points.  Even for famous brands, there are offerings of several distinct quality levels to choose from. True, you may be overpaying for some name brands.  But remember that sometimes, in fact, you only do get what you pay for.  There will often be a difference in the performance and longevity between a cheap, sometimes foreign, manufactured part and a much more expensive brand-name part, even though both represent that they have identical specifications.  Second, regardless of their quality, some components may show minor incompatibilities or even completely conflict with others, materially affecting (or preventing) performance.  Some parts simply work better together than others.  Therefore, you have to look at the overall design of the computer to maximize its performance, even after you’ve selected all of the components. Third, test results show that, even among similarly priced products (like hard drives), some are materially better of worse than others.  So, how do you know about these things?   It’s nice to have a hardware geek for a friend but, if you don’t, there’s lots of readily available web advice in this area as well. For first-timers, there are even sources like which make your choices easier.  You can adjust your budget, and the app won’t let you buy parts that are incompatible with your chosen system.  But, remember, just because you read it on the internet doesn’t mean it’s correct (use the “median” method outlined in FAQ #52).

First, you’ll need to select a case.  The size and shape of the case will determine what type and limitations of some of the hardware that will fit inside it, so it’s quite important and a first consideration. It’s always a good idea to get a case with lots of room for you to work and to store left over cables.  You can’t go wrong with a ATX full tower case.   For more about this see cases.

The power supply (“PSU”) that fits into the case as well as its overall strength must also be considered up front.  The more hardware components in the case, the higher the wattage of the power supply must be.  Also, the connectors to the motherboard will vary with the size and type of power supply.  Power supplies can be modular, semi-modular or non-modular.  The primary difference is that a modular PSU has detachable cables, so that you only need attach those cables you need.  A semi-modular PSU has only the bare minimum cables attached, leaving the rest up to you.  A non-modular PSU arrives with all cables attached, you can tie up those that you don’t require.   For more, see power supply.

A main board (“motherboard”).  [See Boards & Chips for more about what’s on this board, if you’re interested.]  This is clearly the most important component of any computer, even more than the processor (discussed below).  That’s because everything else must physically connect to or otherwise be compatible with the motherboard.  These days, main boards often include all possible connections that you may require.  That would include keyboard and mouse connections, USB ports, video, audio, ethernet and other common ports.  However, depending on your specific needs, you may decide to “beef up” certain aspects of the computer, like the audio or video, which would mean that you will have to upgrade the board with additional “riser” cards for these features.  Make sure that the connectors on the bottom of the cards fit into the proper slots on the motherboard (e.g. PCI, PCI express, AGP, etc.).  You’ll notice that most of the other hardware descriptions here say that the motherboard connections for the cables and devices are the most important consideration for selection.  If the motherboard won’t accept the proper connection, the computer just won’t work.  [Click HERE for a diagram of a typical motherboard and its connections.]  And some of the motherboard manuals have quite a lot of useful information about connections in them, so don’t forget to read it over.

Next, you’ll have to consider the “brain” of the computer, the processor.  Whether it’s Intel, AMD or another popular processor, it comes in speed, cache size and a number of other attributes that must be evaluated based on your requirements.  Most important, it has to be compatible both in form and function with the motherboard you have chosen.  Not all processors fit all boards, of course.  Compatibility is the issue here.  And check to see if you have to purchase the processor fan separately (the norm) as well as the heat sink or if it comes with the processor itself.  [For the correct terminology when referring to chips, chipsets, CPUs and processors, click HERE.]

Now, let’s get started on your computer’s memory.  First, the temporary memory, the RAM.  You’ll have to figure out how much you’ll be working on at any given time and then calculate how much RAM you will need.  The type of RAM will be dictated by the slots on the motherboard itself.  These days, it’s usually DDR3.  And you’ll probably buy a pair of RAM chips (e.g. (2) 8Gb chips for 16Gb total RAM).  For more, see RAM.

You’ll also need a hard disk drive and an appropriate cable to connect to the motherboard.  Most likely, you’ll also require a combo CD/DVD read/write drive and a cable for that. Make sure that the motherboard supports the cables and types of drives you have selected.  These days, SATA drives and cables have pretty much replaced the older IDE drives and some SSDs are available (see Drives).  These days, not many people use floppy or Zip drives, but instead rely on more commonly available external drives or flash drives.  But if you require these types of connections, they can often be added via riser cards.

A keyboard and a mouse as well, if you don’t already have them, are  necessities.  Remember, again, that the motherboard must be compatible with these devices.  Most common motherboards have USB ports for the keyboard and mouse, not PS/2 ports (see connectors) or the old DIN connectors.  Serial and parallel ports and SCSI ports are connections of the past as well, so if you have older (“legacy”) devices, make sure that they can be connected to the new computer or at least there are hardware adapters and current drivers for your O/S.

And, of course, you’ll need a monitor.  Maybe even a printer or speakers.

Depending on your needs as well as the basic hardware selections, you may require other hardware:  Additional cooling fans, a Wi-Fi card and antenna, an internal SD card reader, Bluetooth, a webcam and the like.


Mainly your operating system (“O/S”).  Whether it’s Windows, Linux, Unix, or Apple OS X, it will turn the assembled hardware into a machine that is ready to accept processing commands.  But first, it must recognize each individual hardware device and be able to communicate with it.  The software for this purpose is called a “driver” and most, if not all, of the necessary drivers will either be pre-loaded in the O/S itself or contained on disks that come with each item of hardware, to be installed during the setup of the computer.  As I said above, the installation process for the operating system is much more automated than it used to be, often self-executing.

Also, the programs.  Whether it’s for word processing, drawing, accounting or some other purpose, the programs for those purposes must also be installed, after the O/S has been completely set up.

Next, the assembly:

It doesn’t really matter what order you follow.  Many people install the power supply into the case first, then go from there.  Others assemble everything onto the motherboard before screwing it into the case.  It really doesn’t matter, whatever is convenient for you, so long as everything is connected properly in the end, right?  So here are the basics:

1.  Open up the case.  Then open up the box with your motherboard inside.  Take out the I/O shield (the metal plate that protects the ports on the back of the board) and then snap it into the case with the ports in the correct space on the back of the case.  It has to match the plugs on the motherboard, which you’ll screw into the case next.

2.  Now install the processor.  Follow the instructions for your individual processor.  For most Intel processors, you match the gold arrow in one corner of the processor with the gold arrow on the socket in the motherboard.  Easy.  Usually you will have to pull down a lever to lock the processor into place.  Then attach the cooler fan to the top of the processor, again according to the instructions in the manual.  Usually, the processor already has sufficient thermal paste on the top, but to play it safe, you might want to purchase a small tube in case it doesn’t.  It’s inexpensive and, if you don’t have a sufficient thermal seal, the processor will overheat and may damage the computer.  Small price to pay to play it safe.

3.  Now install the RAM.  Line up the notch in each chip with the notch in the socket and press firmly until you feel the chip snap into place.

4.  The hard drive is next.  Depending on the case, the drive may be held on by screws, or by clips, or by a bay that swings out.  Check your manual.  For cooling purposes, if you have more than one drive, leave some space between them to keep the computer cool.

5.  Install your CD/DVD or floppy drive or other device (e.g. SD card reader) by removing the drive bay cover, inserting the device and screwing or clipping it into the case receptacle.  You may not have to worry about this but some devices, like CD/DVD players, may daisy chain onto the cable connections for other devices, like hard drives.  When this happens, some of the devices will have “jumper” settings that must be adjusted.  You will have to decide, based on the manual or a sticker on the device, whether you must put a tiny plastic piece over either the master, slave or cable select pins.  Cable select works for most devices, as it lets the operating system make the selection for you.

6.  Now you’re ready for the power supply, which ties everything you’ve done so far together.  Mount it in the slot at the top back of the case with the screws provided.  Then connect the cables as follows: The large 24-pin cable connects to the motherboard in only one direction, usually with the clip facing inwards.  Push until you feel it click into place.  Same with the 4 or 6 pin cable that also plugs into the motherboard, often close to the processor.  Make sure that your power supply came with the correct pin configuration for your specific motherboard (e.g. ATX). Now, depending on the devices you have put in your case, you will have to install both power cables as well as data cables to those devices.  These will include, at a minimum, your hard drive and CD/DVD drives.  Some video cards require a 6 pin PCI cable.  Any additional fans may require a Molex power cable.  And so forth.  Look at connectors to see photos and definitions for most cables you may encounter. Last, you may find that your motherboard came with very thin wires intended to connect from the board to the front of your computer, for things such as power, reset, HDD, USB, speaker/headphone, etc.  Follow the instructions in your motherboard manual to see where exactly they plug onto the board.

7.  When you’re sure everything has power and is connected to the motherboard, use some sort of ties to make sure that the remaining cables are bundled and placed out of the way.  Also make sure that the connected cables aren’t near the processor or any of the fans, as that would affect performance and make noise if they come into contact with the fans.

8.  Turn it on.  If everything is done correctly, it’ll work.  Don’t be upset if it doesn’t start right up, quite often it doesn’t and it’s usually something simple.  Listen to the “beeps” and check the motherboard manufacturer’s website to decrypt their meaning, then make the adjustments and try again.  If you’re still stuck, unplug all of the  cables, then re-plug them, one at a time, until you discover the source of the problem.  The most common noobie mistake is the connection from the PSU to the motherboard;  there are 8-pin and 4-pin connectors to the sockets and sometimes you have to separate the 8-pin connector to fit in the first four ports of the socket.

9.  Once you’re sure everything is connected correctly, it’s time to load the operating system.  But before you do so, be sure to connect the keyboard, mouse and monitor and check the BIOS (or, in some newer Win 8 computers, the UEFI).  When the computer first starts up, it will tell you the BIOS setup key to press, usually DEL.  When you do so, you will see a series of menus showing the various hardware aspects for the computer.  You might want to review all of the BIOS/UEFI settings, as it may be useful to know this later anyway.  Pay particular attention to the RAM (correct amount?), SATA (make sure it’s AHCI), the boot order (make sure it will boot from CD first, so you can load the O/S), your hard drive and its capacity, etc.

10.  When it looks good, put the Windows installation disk in the CD/DVD drive, shut down the computer, then reboot it.  Then simply follow the instructions after the “Install Now” prompt.  You may have to format the hard disk drive or install any drivers that Windows doesn’t recognize (perhaps for the riser cards, which may have specialized software that came with it on a CD).  You should check the Windows Device Manager to see if any hardware drivers aren’t installed.  Then either use the disk that came with the hardware or Google the manufacturer’s site and download the appropriate driver for installation (remembering whether you require a 32 or 64 bit driver, depending on the version of your O/S.

11.  Lastly, bring your computer up to date.  Install all Windows Updates (find the link in the Control Panel). 

12.  Install an anti-virus and possibly an anti-malware program.  Install your programs and update them as well.  Then customize your machine by adjusting the desktop, screen saver, password protection, power settings, etc.  In fact, you should go through the Control Panel item by item to your satisfaction, you should know it anyway.

If you’ve done all of the above steps correctly, you’ve now built your own computer.  Not only should it perform the way you want it to, but you’ve probably saved a lot of money and learned a lot about the machine that will save you additional time and effort over the many years you own and use it.  And you’ve learned something, too.

But, of course, this isn’t a perfect world.  The incorrect part may be delivered or it may be defective (yes, this happens a lot; many sensitive parts get damaged in shipping and, unfortunately, quality control isn’t what it used to be).  And the more complex the machine, the more possible combinations of hardware and software, an the more of a chance of some sort of conflict that must be resolved.  If you try to solve the problem yourself and can’t, most local (not “big box”) computer stores (or, course, Computer Coach) will be happy to assist you and get you back on track for a minimal charge.

Links: As I said up front, there are lots of sites that you can go to in order to find information or even videos about selecting components and building your own computer.  Here are a few good ones:

>>How To Build Your Own Computer Cables (this site)

>> Spec Parts:; Logical Increments PC Buying Guide

>> Parts Suppliers:;;

>> Forums:  Reddit; Tom’s Hardware

>> Step-by-Step Building Guides:  Step-by-Step Guide to Building a PC; PC Pro Guide; How to Build a Computer From Scratch





























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