How to Assemble a Computer




Introduction: How to Assemble a Computer


These instructions will guide you through the process of building a functional computer. In order to get the most out of these instructions, it is important that one has prior knowledge of all the components that are used in a computer. For this project, you will need:

  • Processor (CPU)
  • Computer Case
  • Optical Drive (DVD RW and SATA capable)
  • Memory (RAM)
  • Power Supply
  • SATA Cables
  • Motherboard
  • Processor Fan
  • Case Fan
  • Hard Drive
  • Assortment of case and drive screws if not included with the case/parts.
  • Windows operating system installation disk


  • Screwdriver
  • Heat sink compound (thermal paste)
  • Containers to hold screws
  • Pliers
  • Small flashlight
  • Adjustable wrench
  • Anti-static strap
  • Rubbing alcohol

Caution: It is important to research that the parts are compatible with each other, and that the PSU provides the proper voltage (this changes based on country, parts, etc). It is important to check the motherboards CPU support list to see if the processor is listed. Incompatible parts may require a need to flash the BIOS which will require a transitioning processor in order to complete this process.

As you proceed with the steps make sure to route any wires behind the motherboard, (if the case
has that wiring arrangement) or around the motherboard. Tuck and tie the wires into empty case areas to keep the drive bays as clear as possible. This not only creates a clean and organized work area, but it also provides better air flow to ensure that the system stays cool.

Step 1: Choosing Parts

  • Choosing the components for a computers might seem like a daunting task. However, in recent years it has become much easier to choose what pieces you would like without having to spend a lot of time researching about all kinds of computer components in many different sites and having to look at benchmarks. These are things that are still recommend that you should do, at least to some extent. If you would like a simpler approach then the best resource available to do so is the website
  • This website allows you to pick each and every single piece that you would need. It also has a separate page that consist of builds that other people have created in case you would like that option. The reason why this website is such a great resource is because it allows you to compare prices of many different kinds of components across a multitude of websites so that you always get the best deals. Furthermore, it includes comments from others which give you an idea of how well a certain components perform when compared to others.
  • After clicking Start a System Build on the homepage, you will be presented with the screen in the picture above. When you click one of the blue buttons for each of the different components, you will be presented with a list of many different components, their specifications, ratings by others, the cheapest price for that certain piece, and the option to add that component to your build. By clicking on a certain piece, you will be presented with another list of different websites that sell that piece and the price that pertains to that website. Under that you also have a combo list, in case that components is being bundled up with another piece. You also have a price history for the piece, as well as reviews by others who have purchased the piece. After you have finished choosing all of the desired components, all that is left to do is to visit each of the websites that you have chosen to purchase the components from and purchase them.

Step 2: Prepare Case for Assembly

The first step in building a computer is to prepare your case for the build. You want to familiarize yourself with your case so that you avoid making costly mistakes. You want to remove both of the side panels of the case by locating the screws that hold both of them in place. They are located behind the case, where the I/O panel is located. After removing the screws, you want to slide the panels back and lift them away from the case.

After opening the case, remove any packaging that might be found inside your case. You will also want to remove the covers for your optical drive.

Lastly, you should determine how to best route the multitude of wires you will be using in order to prove good cable management. This is not necessary, however, it is highly recommended as good cable management helps to keep the temperature of your case down by providing better airflow and it also makes it much easier to switch components at a later time.

Step 3: Grounding

The next step is to ground yourself. There are several ways to do this. The best and safest method is to purchase an Anti-Static strap for your wrist, which are sold at most electronic stores, and connect it to any metal parts of your computer case. With this strap you prevent the buildup of static electricity within your body and thus avoid damaging any of the components.

The other method that you can use to ground is by touching a metal frame. By doing this you discharge the static electricity within your body and avoid damaging any of the components. It is recommended that if you are using this method, that you perform the build in an area where you can minimize the buildup of static electricity, such as avoiding carpets and other similar objects that can cause a buildup of static electricity.

Step 4: Install PSU

The next step is to install the Power Supply Unit. The first thing you want to do is to locate the area in your case in which the PSU will be placed in. Generally this area is in the bottom left of your case, however, some cases the PSU is mounted on the top of the case.. Place your PSU within your case and make sure that the socket faces outside the case. Next you will want to fasten the screws through you case and make sure the PSU is securely in place.

Note: Since various countries supply electricity at varying voltages , it is important that you switch your PSU to accept the correct voltage for the country in which you will be using it. For example, here in the US your PSU should be set to the 110V/115V setting. The voltage selection switch is typically located near the on/off switch on your PSU. Some power supplies do not have this switch and instead automatically detect the input voltage and set it themselves.

Step 5: Install the Motherboard

The next step is to install the motherboard. The first thing you will want to do is to prepare your case for the motherboard. You must locate on your motherboard where each of the screws for your motherboard will be placed in and install each of the standoffs. Then take your motherboard and line it up amongst the standoffs and push it down into place.

Next screw the motherboard down and make sure that it is securely in place so that it might not fall off later on. As your are placing your motherboard in place, you also want to line of the I/O panel of your motherboard to that of the case. The I/O panel consists of the connectors for your monitor, USB devices, and other peripherals.

You will also want to install the mounting brackets for your CPU fan on the back of the motherboard.

If you need a diagram of the different sections of a motherboard look at the following image. Your motherboard will more than likely not be the same, however, many of the sections on a motherboard are similar.

Step 6: Install the CPU

The next step is to install the CPU within your motherboards CPU socket. Located the socket on the motherboard, which is generally located within a heatsink and the RAM slots. On the socket there is a small metal arm that holds the CPU in place on the motherboard. Lift the metal arm out of the way and open access to the CPU socket.

Next remove the plastic cover on the CPU socket, however, it is advised to save this if you have to RMA or warranty return the motherboard. With the latching mechanism now open, you can gently place the CPU into its socket. Caution: You should not be required to use any force at all. Applying force could cause the pins in the CPU to bend and cause damage to the unit. To make sure the CPU is oriented correctly within the CPU socket, you will want to line up the notches on the sides of the CPU to those of the socket. Furthermore, located the golden arrow on the underside of the CPU on one of the corners and line it up amongst the corresponding arrow on the CPU socket.

Step 7: Install the CPU Fan

The next step is to install the CPU fan. Apply a small amount of thermal paste onto the CPU. The most common method is to only apply about a pea-size dot on the center of the CPU and gently spread along the CPU until it covers the top of it.

Next you will want to place the CPU fan on top of the CPU and attack the screws onto the motherboard mounting brackets that you placed before to properly secure the CPU fan into place. Make sure that as you are placing the screws into place, that you slowly tighten each of the brackets slowly in a criss-cross method. In order words, you want to slowly tighten each screw a little bit each time, switching in a criss-cross method between each screw until they are all in place firmly in a similar fashion.

Various heatsinks and fans might require different methods in order to mount them onto the CPU. Consult the manufacturer’s instructions for more detail on how to mount your specific equipment.

Step 8: Install RAM

The next step is to install the RAM into its sockets. The ram sockets are located just to the side of the CPU. If your motherboard comes with four slots, it is important that you check which slots you must placed the RAM in order of. This can be done by checking the motherboard manual that comes with your motherboard.

After checking which slots you should use, open the latches on the sockets, align the RAM within the socket, and gently press down on both ends until the RAM snaps into place into the socket. If the socket has tabs, make sure that they are locked into place as well.

Step 9: Install Hard Drives

The next step is to install the hard drive. Depending on your case, you may need to either remove screws from the hard drive bays or simply remove the plastic clips in order to open up the hard drive bays. Consult the manual for your case for more detailed instructions.

You are going to place the drive into the internal 3.5” slot, in the section of your case for the hard drive, which in most cases is located in the front. Use the appropriate screws to to screw in the case into the slot and slide the hard drive into the mounting area.

Next you must use the included SATA cables and connect one end of the SATA port onto the hard drive and the other end of the SATA cable onto the port on the motherboard.

Step 10: Install the Optical Drive

The next step is to install the optical drive. First you must locate the optical drive bays on your case.

Note: These are typically located towards the front of the case near where the hard drives are placed in..

Then you must remove the bezel in the case where you wish to place your optical drive. After that place the drive into the external 5.25” slot, Next just like the hard drive you will use the appropriate screws to screw in the drive into the slot. Then connect one side of the SATA cable onto the optical drive and the other side onto the port on the motherboard..

Step 11: Install the Video Card

1. The next step is to install the video card. The first thing you will want to do is to located the PCI express slots on the motherboard where you will like to place your motherboard. You must then remove the case’s rear metal brackets.

Note: Depending on the size of the card you may only need to remove one of the metal brackets

2. Next remove any plastic covers on the connectors on your video card. You must then unlock the corner clasp on the PCI express slot on the motherboard and insert the video card into the slot. Press down on the video card, until it is fully into place, and then relock the corner clasps on the slot. Finally, screw your video card’s metal brackets to the case rear until it is fully secure in place.

Note: It might take more pressure than you think to fully get the video card into the slot.

Step 12: Test Your Connections

The next step is to test your system. First, plug in your PSU power cord into PSU and then into a wall outlet and start your computer. Test to see the following are running - all 3 fans - case, CPU, PSU, (and video card fan(s) if separate video card installed). Then test the power button (PC comes on and off) on your case and the reset button (HDD LED light blinks once) on your case. Next test to see all 3 LED lights work - PLED light (power on light that stays on when PC is on), DVD LED light (comes on at start then goes off), HDD LED light (blinks initially).

If there are any problems while you are testing the connections make sure that the wiring was correctly done and look up any type of error codes that you may receive.

Step 13: Put the Panels Back on the Case

Screw back the case left and right panels. Make sure that they slide into place correctly.

Throw away any trash, and keep any leftover parts in a secure location for future use.

Step 14: Install Your Operating System

The next step is to install your operating system onto your hard drive. The first thing that you will want to do is to set up your boot sequence to boot from your optical drive first. To do this, you will want to enter into the BIOS, which can be done by pressing the delete key or appropriate key once you startup the computer. Once inside the BIOS, make sure that your CPU, RAM, and hard drive are properly recognized, Then make your way to the boot sequence section and change it to your optical drive for now. Next place the CD-ROM for you desired operating system into your optical drive and restart your computer. Once the setup screen has been displayed, follow along the process until you have successfully installed the operating system. Once the OS has been properly installed, you will want to go back to the BIOS and change the boot sequence to your hard drive, so that on startup your hard drive is used instead of the optical drive.

Step 15: Conclusion

Congratulations! You should now have a fully assembled and functioning computer. At this point, it is advised that you make sure all the drivers for your components are installed and up to date. To update drivers, go to the support page of the website of the company that you purchased the components from. Follow the instructions from there. Afterwards, you can install any programs you plan to use. It is highly recommended that you install an anti-virus program to protect your newly-built computer from malicious software that you might encounter while online. A great website to use to get your computer up and running quickly is This website will allow you to install many different widely used programs at once.

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    7 years ago on Introduction

    I usually install the CPU and cooling fan onto the board before I mount it in the case. It's a lot easier because you have room to work. Sometimes the power supply is so tight that you can hardly work around it. I also put the ram in. It is easier to identify the slots and make sure its seated. Also you have a backing for the board so you can put a little pressure on it if you have to press them hard to get them to lock in. Place the board on the antistatic bag and the pad if it has one while you work on it. Once those components are mounted you can put in the back plate (the metal plate where all the plug ins are) and test the fit, verify that you have all the posts in the right place and nothing is in the way. I also usually put the board in before I put in the power supply. This way you don't have cables in the way and again it gives you more space to work. Doing it this way makes things much easier especially if you have a more compact case.


    Reply 7 years ago

    I ll have to agree with you. cpu, cooler and ram are to be installed before you mount the motherboard to the chasis.