How to build a computer

Table of contents:

How to build a computer
How to build a computer

This wikiHow teaches you how to build a desktop using custom components. Success when building a computer will depend largely on the goals you set, the budget you have, whether you get the right pieces, and whether you put everything in the correct order.


Part 1 of 4: Planning Your Computer

Step 1. Determine how you will use your computer

Before buying any component or setting a budget, you need to know what you are going to use your computer for. Standard desktop computers, used for things like navigating or doing things in small programs (for example, Microsoft Word and Excel) can be built with older, less expensive parts. However, if you want a computer for editing tasks or for playing video games, you will need a more powerful one with updated parts.

On a basic desktop, you can expect to spend less than $ 500. If you need a computer for editing work or to play video games, the price can range from $ 500 to a few thousand dollars

Step 2. Set your budget

It often happens that you start to buy attractive parts without thinking about a budget and in the end you realize that the money has run out and you still need to buy equipment to finish building the computer. Set a soft limit (for example, $ 300) and a maximum limit (for example, $ 400) and try to stay within that range.

Use common sense when shopping. For example, if the processor you can buy on your budget costs $ 100, but a newer, better $ 200 model is on sale for $ 120 at a local tech store, it's probably worth spending that extra $ 20 as a long-term investment

Step 3. Take into account all the components that you will need to buy

Regardless of how expensive your computer ends up being, you are going to need the following components for your project:

  • Processor: works as the "brain" of the computer.
  • Motherboard: serves as an interface between all the components of the computer and the processor.
  • RAM: random access memory. Determine the amount of memory a computer has to process items. The more RAM you have, the faster the computer will run (up to a point).
  • Hard disk: stores data. You can buy a traditional hard drive or go for a solid state drive (SSD), which is more expensive, but works exceptionally fast.
  • Power Supply - Provides power to individual components of the computer. The power supply is also the interface between the computer and the outlet you plug it into.
  • Box: necessary to store and cool the components.
  • Graphics card: used to render or represent computer images. While most processors have a built-in graphics processing unit (GPU), you can also buy a dedicated graphics card if you want to play video games or use your computer for intensive editing tasks.
  • Cooling system: keeps the inside of the case at a safe temperature. Only necessary on computers used for video games or editing. On regular computers, air circulation from the fan is sufficient.

Part 2 of 4: Buy the Components

Step 1. Learn where to buy components

Physical stores like Best Buy sell computer components, but you can usually get better prices by shopping online. Some of the online stores that you can use are Amazon, eBay, or NewEgg.

Do not rule out the possibility of buying used parts, especially if they assure you that they are "like new" or as if they had never been used. Sometimes you get deeply discounted parts that work just like new

Build a Computer Step 9
Build a Computer Step 9

Step 2. Research each component you want to buy

Read magazines and go to online consumer review sites to find more information. Remember: this is one of the most important steps, because it all depends on whether the hardware is working properly.

  • Look for good reviews about your favorite product, both on the site where you are thinking of buying it and elsewhere.
  • Once you've found a component with enough positive comments, look for negative comments on that component. You may find that the component is excellent for some uses, but not as appropriate for the one you want to give it.

Step 3. Find a processor

The processor (or CPU) is the part that most influences the performance of a computer. The faster the processor is in gigahertz (GHz), the faster it can process data and the more RAM it can use.

  • The processor usually takes up the majority of the budget.
  • Processors typically come in two-core or quad-core varieties. Unless you're building a high-performance gaming computer, it's best to choose a dual-core one.
  • The two main manufacturers of processors are Intel and AMD.

Step 4. Get a processor-compatible motherboard

You should choose a motherboard that is compatible with the processor. To check this, you can look up a list of the processors that your motherboard supports (some sites also offer lists of the motherboards supported by a particular processor). Other desirable characteristics in a motherboard are the following:

  • Built-in WiFi (this will ensure that your computer can connect to wireless networks)
  • Bluetooth
  • multiple RAM memory slots
  • graphics card support (if necessary)

Step 5. Buy RAM memory cards

RAM memory is responsible for storing the data of running programs, so it is important to have a sufficient amount. Before buying RAM, be sure to check which type is compatible with your processor and motherboard.

  • There is a limit to the amount of RAM a computer can use. This limit will be given by the maximum memory of the processor. For example, if you install 16 GB of RAM in a computer that only supports up to 8 GB, you would be wasting your money.
  • Generally, you should buy DDR3 or DDR4 RAM, depending on your motherboard. Your motherboard documentation will include information about the type of RAM it supports.

Step 6. Buy a hard drive

In terms of comparison, buying a hard drive is easy: most drives are compatible with virtually all motherboards and processors. However, you need to make sure the disc fits in the case. You may want to buy a SATA hard drive, which can hold at least 500 gigabytes, and be sure to choose a reputable brand, such as Western Digital, Seagate, or Toshiba.

  • Average hard drives have a speed of 7200 r.p.m.
  • Hard drives also come with IDE connections instead of SATA, but SATA is a more modern interface and therefore more compatible with more modern motherboards.
  • If you want a smaller hard drive, with a higher data recovery speed, you can buy a solid state drive (SSD). These drives are significantly more expensive than standard computer hard drives.

Step 7. Buy a graphics card if necessary

Dedicated graphics cards are essential for playing the newest video games, but not essential for everyday tasks. If you watch or edit high-definition videos frequently, or play video games a lot, you might want to buy a graphics card.

  • As with the other components, you must ensure that the graphics card is compatible with your motherboard.
  • Virtually all Intel CPUs come with integrated graphics, so you don't need a dedicated card if you plan to use your computer for office work, surfing the Internet, using email, or playing some online games.
  • Graphics cards are also known as "video cards".

Step 8. Make sure your power supply can handle the full load

The power supply will take care of supplying power for all components of the computer. Some boxes come with a font already installed, but in other cases you must buy it separately. The power supply must be powerful enough to provide a load to all components. You should not think that if it is "too powerful" it will be a waste of electricity, since the source will supply only the watts that your computer needs and the number of watts actually refers to its maximum capacity.

  • Choose a power supply from a reputable manufacturer, such as EVGA or Corsair.
  • If you are using your computer for video games, you will need a 550W or higher source.

Step 9. Choose a box that is functional and at the same time attractive to the eye

The case is what holds the components of a computer. A few boxes come with a power supply included, but if you're building a gaming computer, it's best to get a separate power supply as the ones that come with the boxes are usually not of very good quality.

  • The size of the enclosure will depend on how many hard drive bays or "bays" and how many card slots you have. It will also depend on the type and size of motherboard.
  • Make sure you choose a box that will fit all the components, including the hard drive.

Part 3 of 4: Assembling Your Computer

Step 1. Ground yourself

Wear an antistatic wrist strap to avoid electrostatic discharge (ESD) that can be extremely damaging to the electronic components of a computer.

If you can't find an antistatic wrist strap, plug the power supply into an electrical outlet (but don't turn it on) and put your hand on the grounded unit every time you touch an ESD sensitive item

Step 2. Open the box

To open it, remove the screws on the side panel (or slide it towards the back of the case).

Step 3. Install the power supply

Some boxes come with the power supply already installed, while in other cases you have to buy the supply separately and install it yourself. Make sure the font is installed in the correct orientation and nothing is blocking the fan outlet.

The power supply usually goes near the top of the case. You can determine where to place the font by looking for a missing section on the back of the box

Step 4. Add the components to the motherboard

It is generally easier to do this before installing the motherboard as the case may limit the ability to connect some components:

  • Plug the processor into the motherboard. Find the port for the processor on the surface of your motherboard and plug the processor cable or connector into that port.
  • Install the RAM memory on the motherboard by finding the RAM memory slots and inserting the cards in the correct position (they only fit in one position).
  • Plug the power supply into the corresponding section of the motherboard.
  • Look on the motherboard (but don't connect it) for the port for the SATA hard drive. You will use it to later connect the hard drive to the motherboard.
Build a Computer Step 12
Build a Computer Step 12

Step 5. Apply thermal paste on the processor, if necessary

Put a small dot (about the size of a grain of rice) of thermal paste on the CPU. Putting too much thermal paste can lead to disaster, as if paste gets into the motherboard socket, it could short-circuit the components and the value of the motherboard would decrease if you plan to sell it later.

Some processors that come with a heatsink do not need thermal grease, as the heatsink comes with factory applied thermal grease. Before putting thermal grease on the processor, check the underside of the heatsink

Step 6. Connect the heat sink

Steps vary by model, so read the specific instructions for your processor.

  • Most common heatsinks sit directly on top of the processor and hook onto the motherboard.
  • Some replacement heatsinks may come with brackets that plug under the motherboard.
  • If your processor already has a heatsink installed, you can skip this step.
Build a Computer Step 17
Build a Computer Step 17

Step 7. Prepare the box

You may have to tap the trays on the back of the box to get the components to snap into position.

  • If the case has separate shelves to hold the hard drive, install them using the screws that come with them.
  • You may need to install and connect the case fans before installing other components. If so, follow the instructions in your box for installing the fans.

Step 8. Secure the motherboard

Once the standoffs are installed, place the motherboard in the case and push it against the back plate. You will need to make all the rear ports fit into the entry and exit holes on the rear plate.

Use the provided screws to secure the motherboard to the standoffs through the shielded screw holes on the motherboard

Build a Computer Step 19
Build a Computer Step 19

Step 9. Plug in the box connectors

They are usually located all together on the motherboard, near the front of the case. The order in which you plug them in will depend on what is easiest. Make sure to connect the USB ports, the power and reset switches, the power LED, the hard drive lights, and the audio cable. Your motherboard documentation will tell you where each connector plugs in.

Normally, there is only one way to plug the connectors to the motherboard. Don't try to force anything in

Step 10. Install the hard drive

The process may vary slightly depending on each case, but generally the following must be done:

  • Remove the front panels of the case (if you are installing an optical drive, it is usually installed near the top of the case).
  • Insert the hard drive into its slot (again, it usually goes on top of the case).
  • Tighten as many screws as necessary to hold the disc in place.
  • Plug the SATA cable from the hard drive into the SATA connector on the motherboard.

Step 11. Connect the power supply to the components that need it

If you haven't yet connected the power supply to the components that require power, be sure to do so now. You must connect it in the following places:

  • motherboard
  • graphics cards
  • hard drives

Step 12. Finish assembling the computer

Once you have placed and connected the different internal components of your computer, the only thing that remains is to make sure that none of the cables interfere with the circulation and closures to box.

  • If you purchased a cooling system, you must install it before proceeding. To do this, consult the installation instructions for your cooling system.
  • Many boxes have a panel that slides back into position, or that screws into the side of the box.

Part 4 of 4: Run Your Computer

Step 1. Plug the computer into an electrical outlet

Use the power supply cord to connect your computer to a wall outlet or power strip.

You may first need to connect the cable to a power inlet on the back of the computer case

Step 2. Connect the monitor to the computer

Generally you have to use the graphics card outlet that is near the bottom of the case, although some motherboards have that port on the right or left side of the case.

The output is usually a DisplayPort or an HDMI port

Step 3. Turn on the computer

Press the power button


from the front or back of the box. If you connected everything correctly, your computer should now turn on.

If there is a problem during the boot process, or if the computer does not start directly, unplug it from the power, open the case again and check the connections

Step 4. Install Windows or Linux.

Windows is compatible with all personal computers and can take full advantage of all features (for example, Bluetooth), but if you don't have a Windows product key, you must purchase a copy of Windows. Linux is free, but it may not allow you to take advantage of all the hardware in your computer.

If you don't have an installation USB stick, you'll need to create one on another computer in order to install your operating system

Step 5. Install all drivers

Once your operating system is installed, you will need to install all the drivers. Most of the hardware you purchased will need to come with discs that contain the driver software that hardware needs to function.

Newer versions of Windows and Linux install most drivers automatically over the Internet


  • Some power supplies come with a built-in 115 to 230 V converter. If you are in the United States, use the 115 V setting.
  • All power cables fit into only one position, which is the correct one. However, you may still need to press down on the cables to get them connected. If you are using a new 8-pin power supply with a 12V EPS connector and an 8-pin PCI Express connector, do not try to connect the cables forcibly.
  • You can carefully bundle all cables with cable ties and then locate them where they won't block airflow.
  • If you purchased an OEM (Original Equipment Manufacturer) edition of Microsoft Windows and have a license label on it, you can affix the label to the side of your computer for later reference when prompted by Windows Setup.
  • If you are installing a water cooling system instead of a regular fan, you should run a 24-hour test to make sure there are no leaks before installing the computer.


  • Do not touch the resistors or pins of the CPU or socket.
  • Be very careful when working near the sharp edges of the metal sheets of the computer case. You can cut yourself easily, especially in small boxes.
  • Avoid causing electrostatic discharge when installing components. Wear an antistatic wrist strap or ground yourself regularly by touching a metal part of the case before handling components.
  • Don't buy computer parts from untrusted online sites. You could be the victim of a scam or they could sell you defective parts.

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