This article is part of our PC-building beginner’s guide. You can view the entire guide here.
How to Assemble a PC
This is the part you’ve been waiting for: assembling the parts and completing the masterpiece that is your PC. Keep in mind that it’s impossible to write a perfect step-by-step guide to assembling a PC since there are too many variables at play, especially in case design. As such, some steps may vary slightly when building your own PC, but the bulk of the process should follow these steps. I would recommend looking up videos of someone assembling a PC with your specific components, or ones that are similar.
Before you start, we’d like to throw in one last note: your parts aren’t nearly as fragile as you think. If it’s your first time building, you may feel like you’re going to break the motherboard when putting the RAM in (and you might feel like you’re breaking the RAM sticks too), but PC parts are far sturdier than you think. Don’t be careless or use more force than necessary, but know that your parts can handle a lot more than you think.
- Take the side panel off of the case to access the interior. This should be held down by several large screws, which you can typically remove by hand.
- Find the standoff screws. Usually these are found in a plastic bag inside of the case (shown below).There are many small holes in the case, usually labeled with a letter next to them (usually “A” for ATX, “M” for Micro-ATX, or “I” for Micro-ITX). Screw the standoffs into the holes that match your motherboard type.
- Find the IO plate, the shiny metal plate that comes in the package with the motherboard. Place it so that the text is readable and right-side-up when looking from outside of the case. Snap all four corners into place, making sure it is firmly secured.
- Carefully remove the motherboard from its packaging. Set it on top of the box it came in.
- a lot easier to use tweezers, as these cables are truly miniscule.
- For Intel CPUs: Remove the plastic cover from the CPU slot on the motherboard. There is a small spring-loaded metal arm to the right of the CPU cover, which you’ll need to pull to the right and then lift up. Once the CPU cover is up, you’ll see the CPU socket. Remove the CPU from its package and line up the notches on the side with the notches in the motherboard. Wiggle it a little bit if necessary, but don’t push it in. It will settle into place without too much force. Once it is sitting down in the CPU socket, close the cover over the processor, and lock the metal arm into place the way it was to start with. If you have a Ryzen CPU, the process is slightly different, since the pins are in the CPU, not the motherboard. For more information, watch this video.
- Take the CPU cooler from the packaging. Check on the underside to see if it has thermal paste on it. If there’s a gray-silver liquid on the bottom-side of the cooler, you’re good to go. If not, put a small dot of paste on the top of the CPU.
- If the fan has a standard four-pin design (if it came with the processor, it should fall in this category) line up all four of the pins with the holes in the motherboard surrounding the CPU, so that the center of the cooler is directly on top of the CPU. Make sure the pins drop into the holes in the motherboard, then press the pins in from the top. Press the top right and bottom left down first until they click into place, then press the top left and bottom right. Verify that the cooler is secure by pressing on it gently. If you bought an aftermarket or AMD cooler, the setup may be different. Consult the instruction manual for aftermarket, or this link for AMD coolers.
- Take the 4-pin cable that’s attached to the CPU cooler, and plug it into the nearby fan slot, usually labeled “CPU FAN.”
- Find the RAM slots and push down the tabs at the top and bottom (if applicable) of the slots you’re going to use. If your motherboard has four RAM slots but you’re only using two sticks, install them in the 2nd and 4th slot.
- Now take the RAM sticks and line them up with the slot, making sure that the notch in the middle of the slot lines up with the notch in the middle of the RAM module. If not, it’s probably backwards. Press one end of the RAM stick down until it snaps into place, then press the other end down until it does the same. Do this for all RAM sticks.
- If your power supply is fully modular, you will need to find the 12-pin ATX power cable and plug it into the power supply. Do the same with the CPU cable. Now plug the other end of the cables into their respective slots. The ATX power cable usually plugs into a large slot on the right side of the motherboard, while the CPU cable’s plugin is usually found towards the top-left of the motherboard near the processor. The usual plugin locations are shown below.
- Find the SATA power cable that came with the power supply and plug it into one of the power supply’s 6-pin slots. Now connect the other end to your storage drive(s). If you have multiple storage drives, you can connect them to the same power cable, since it will have multiple plugins running along the cord.
- Install the Power Supply. This step will vary based on your case, so you may need to consult the manual. Usually there is an opening at the bottom of the back of the case. Place the power supply inside the case, making sure that the fan faces downwards and the port for the power cord is on the exterior of the case. There will be screw holes in the power supply, and you can use the screws that came with the case to secure it.
- Now find the SATA cable that came with the motherboard and connect it to the storage drive. Plug the other end into the motherboard in the slot labeled SATA, usually found on the right edge of the motherboard. If you have multiple storage drives, you’ll need to run a SATA cable from each one to the motherboard.
- Secure the storage drive(s) in the case. This will vary significantly from case to case. Drives are commonly stored in trays, screwed into the case, or attached to rubber gaskets that lock into the case. You will need to consult your case manual for this step. Make sure that your drive is secured in some manner to the case so that it’s unable to move around and possibly dislodge one of its cables.
- Now install the motherboard in the case. Slide it into place so that all of the ports on the left side of the motherboard stick through their respective slots in the IO plate, and all of the screw holes in the motherboard line up with the standoffs. It may take some force to position the motherboard correctly, since the IO plate has spring-like metal strips facing inwards.
- Once the motherboard is in place, secure it using the screws that came with the case (these are usually found in the same bag as the standoffs). Tighten them a little at a time and make sure that the screws are snug but not overtightened, since this could crack the motherboard. You can tell the screws are tight enough when you are able to press gently on the motherboard without it rocking or wiggling.
- Install the Graphics card. First, make sure to remove the protection cover over the PCIe slot, if present. In most instances there is a panel on the back of the case, directly to the left of the PCIe slots. Unscrew this panel, then unscrew the metal strip that’s on the same vertical plane as the PCIe slot in which you intend to install your graphics card.
- The PCIe slot will have a tab on one or both sides, much like the RAM slots did. Push down these tabs and line up the slit in the graphics card with the notch in the PCIe slot. Press the graphics card into the slot, first on the left side until your feel it snap into place, then on the right. If the tabs that you pressed down in the beginning pop back into place, this means that the graphics card is seated correctly.
- Using screws that came with the case, secure the metal part of the graphics card outside of the case. If there was a metal plate that covered this, screw it back in as well.
- If your graphics card requires an external power source, plug the 6-pin cable(s) into the power supply and connect them to the graphics card as needed.
- Connect the case connectors to the Motherboard. These are usually coming out of the right side of the case, and include cables associated with audio, power, the reset switch, and LED’s. You should always consult your motherboard’s instructions at this point, since most motherboards are a little bit different from one another. Find the section in the motherboard’s installation guide that looks like the one shown below. It will tell you which module to connect these cables to. From there, you need to find the module (it’ll be labeled on the motherboard as well) and connect the pins in the exact layout shown on the manual.
- Put the side panel back on and plug the cable that runs from the wall to the power supply in. Plug in your ethernet cable, HDMI or DisplayPort cables, and any peripherals that you want connected. You’re finished with the build process, and ready to boot.
How to troubleshoot if your PC doesn’t boot
Ideally, when you press the power button for the first time your LED’s light up, your case fans will start spinning and your computer will boot up perfectly. Unfortunately, it doesn’t always go that way. The good news is that the issue is frequently fixed with ease, and can be solved with some simple troubleshooting. Here are some common things to try if your PC doesn’t boot up on the first try.
- Make sure your case cables are plugged in correctly. Consult your motherboard manual and make sure that you lined them up correctly. Since one of these cables controls your power button, if it’s not in the right place your power button may not work, making it impossible to boot.
- Make sure that your CPU cooler is plugged into the connector labeled “CPU FAN.” If you plug it into another connector, your computer may erroneously think that a CPU cooler is not connected, and shut down to avoid overheating.
- Disconnect all but one stick of RAM, and make sure that it is seated perfectly. If the computer boots when this is done, you either have a bad stick of RAM or one of the sticks weren’t seated correctly the first time you put it in.
- Disconnect the power from your storage drive. If your computer boots when this is done, it usually means that either the power cable or storage drive was faulty. Try with a different power cable if your power supply came with more than one.
- If you have integrated graphics, take out the graphics card and try booting. If it boots without the graphics card, reinstall it and try again. Your graphics card may have been incorrectly seated the first time. If this doesn’t work, you probably have a faulty graphics card or power cable running to your card.
- Flash your BIOS. Your motherboard’s BIOS may need to be updated to be compatible with newer processor models. Learn how to flash your BIOS here.
- If all else fails, unscrew your motherboard and place it on a cardboard box. Try booting your system up outside of the case. If this works, check for anything that could have been touching the bottom of the motherboard. It’s possible that you installed an extra standoff that didn’t belong, and was touching the bottom of the motherboard causing a short.
- If none of these options work and your PC still won’t boot, it’s worth ordering a new power supply and trying with that one. If this doesn’t work, it’s likely that your motherboard has been damaged. You can take your build into a shop if you’re willing to spend the money, or order a new motherboard and start from scratch.
If you’re reading this before you build a PC and thinking of all the horrible things that could go wrong, just remember that the majority of the time first-time PC builders are successful. Follow the instructions carefully and be gentle with the components, and you probably won’t have to make use of this troubleshooting section.
How to start up your PC
When you boot up your PC for the first time, you will need to have a boot device. The best way to do this is to buy a USB flash drive and download the Windows boot media using another computer. You can find the Windows boot media creation tool here.
After creating the boot media, insert it into a USB port on your newly-built PC and press a key. This will open the Windows 10 setup wizard, and it will guide you the rest of the way through the setup. It will prompt you to enter an activation key, but you don’t have to have one. If you do decide to buy it, you can download it here.
If you don’t buy Windows 10, the vast majority of your experience will be exactly the same as that of a paid user. The only difference is that you’ll have limited access to security patches, updates, and a few other features, but these may not be worth the hefty price tag.
As a final note, if your PC was built for gaming, you may want to optimize Windows 10 for maximum gaming performance. You can find our guide to doing so here.