Step-by-Step PC Assembly Guide


Last Updated: 15th April 2015 - (Rewording of Introduction)

This is a step by step, illustrated guide on how to put together your parts, complete with detailed photography and commentary; it can be supplemented with a video tutorial such as Newegg’s ‘How to Build a Computer’ series found here.

The process of assembling your own PC is actually very simple in contrast to most people’s expectations. Compared to researching part selection, actual assembly is a much simpler task.

Many prospective builders are often overwhelmed at the idea of assembling their own PC from scratch. However, over the years, the desktop PC industry has become quite standardized. It’s almost impossible these days to install the individual pieces, cables and connectors in the wrong location. Many builders will often relate the process of assembling a PC to building Lego which can only fit together in a single way.

The guide below can be followed step by step, however not everything must be done in an exact order and the order of some of the steps depends on personal preference.

If you are ever in doubt about your components, remember that manuals contain a wealth of information. Indeed, for small form factor builds it is important to follow the assembly instructions found in the case manual, as smaller form factors often require a particular assembly order.

Some people prefer to test boot their PC outside of the case (using a box or non conductive surface as a base for the motherboard). However, given that DOA (dead on arrival) parts are a very rare occurrence, this is usually unnecessary. For this reason this guide does not include an external test boot, but indicates when you can do this if you wish to.

What you will need

The tools we used


A Phillips Head Screwdriver

The only real tool you will need apart from your hands to complete the build successfully. A magnetic screwdriver is always helpful for getting screws in tricky positions and to ensure you don’t drop one in an annoying location to reach.


Your first build, in some regards, can be quite frustrating as you don’t quite know what you are doing even if you have guides to follow. The important thing to keep in mind is to not get frustrated or rush, even if things do not work first time.

Optional, but Nice to Have

Cable Ties

Very often cable ties are bundled in with the computer case accessories with the screws. You may want to pick up a pack for cheap if you know your case does not and want a clean cable managed build. An alternative and less permanent solution to this is to reuse twist ties which are often used in component packaging to hold cables together.

Wire Cutters

Simply to cut the excess off the cable ties neatly. Can easily be replaced by a pair of scissors or a particularly sharp set of teeth (though we are not liable for any dentist bills which may occur!)

Build Precautions

Static electricity is a topic which is often discussed by first time builders as, after all, an invisible threat which has the potential to do damage to delicate and expensive components is a scary thought. A very commonly asked question is what precautions can be taken and which are necessary. In truth, the vast majority of experienced PC builders do not use grounded wrist straps and similar solutions and simply take basic precautions such as touching a grounded object (for instance the metal case of a plugged in appliance). However it is of note that ESD (Electrostatic Discharge) damage does not have to prevent booting or functionality totally and can cause minor damage which may only be evident as BSODs (Blue Screens of Death) in very specific circumstances.

A method some builders use is to plug in to the wall (but not switch on) your new PSU and touch that periodically in order to discharge any static. It is also recommended that don’t build on carpet and avoid wearing socks or loose fitting clothing.

Parts being broken on arrival or breaking in use is a very rare occurrence, however it definitely can happen. For this reason you will want to keep all packaging and boxes for your parts for the length of their warranties (which can be a very long time depending on the component)

The Parts

A Quick Box Shot

PCPartPicker part list / Price breakdown by merchant

Type Item Price
CPU Intel Pentium G3258 3.2GHz Dual-Core Processor $62.99 @ Amazon
Motherboard MSI Z97 PC MATE ATX LGA1150 Motherboard $81.98 @ Newegg
Memory Crucial Ballistix Sport 16GB (4 x 4GB) DDR3-1600 Memory $139.99 @ Adorama
Storage Samsung 840 Series 250GB 2.5" Solid State Drive $159.98 @ OutletPC
Video Card EVGA GeForce GTX 780 Ti 3GB Superclocked Video Card -
Case Corsair SPEC-02 ATX Mid Tower Case $55.89 @ Newegg
Power Supply Corsair RM 450W 80+ Gold Certified Fully-Modular ATX Power Supply $59.99 @ Newegg
Total (before mail-in rebates) $610.82
Mail-in rebates -$50.00
Total $560.82

So without further ado, let's begin!

Before beginning, I should probably state that ChooseMyPC takes no liability from damage caused by following this guide. Now that's out of the way...

First we will be assembling the main components of the PC outside of the case for convenience

The motherboard sub-assembly

Installing the CPU

Take the motherboard out of its protective bag and place it on top of its box (a perfect non-conductive workspace which is the right size to fit the motherboard on). Do not place the motherboard on the anti-static bag it was in - although most commonly used designs for bags are not conductive this is not a good work surface and you are better off just using the box as the bag only offers protection when parts are inside of it.

Removing the motherboard from the box Motherboard on top of its case

Lift the CPU retention bracket lever from underneath its latch by pushing down and out away from the cpu socket. Bear in mind that depending on the socket of your motherboard, this may vary slightly and referring to the manual that came with the motherboard is advisable.

The CPU socket Unhooking the retention bracket lever

Unbox your CPU at this stage and remove it from the protective moulded plastic, holding it carefully by the edges

CPU in plastic CPU in plastic

Now proceeds the most nerve racking part of the build. Lift the CPU retention bracket lever to reveal the socket and its pins. These are incredibly delicate and easy to bend (which motherboard manufacturers will not accept an RMA for), so be very careful when working around the socket.

Revealing the socket

All CPUs have an arrow in one corner corresponding to an arrow printed on or around a corner of the motherboard socket to indicate which way round it fits. The text on the CPU is also an indication of the 'right way up'. In addition to this, Intel CPUs also have notched sides on the upper left and right edges which match up with the shape of the socket. Gently lower the CPU into the socket in the correct position. You should do this so that the CPU stays as horizontal as you can and makes contact with all pins as close to the same time as possible, however there is obviously some room for error. No force needs to be applied at this stage as this is the job of the retention bracket - the CPU should just fit neatly in its place.

Lowering the CPU into place CPU in place

Gently lower the bracket over the CPU, sliding it onto the raised pillar on the motherboard.

Lowering retention bracket

Push down the retention bracket arm and hook it back under the latch where it was originally. This may take some force, and may even cause some rather worrying noises, however if you have placed the CPU in the correct position in the socket no harm will be done and this process ensures that the CPU is in proper contact with the socket. This is an area where more detailed video guides can be watched for reassurance that you are doing the right thing and applying a normal amount of force if you are particularly worried about this step

Securing the CPU

The protective cover will pop off as you lower the lever. Be sure to keep this in a safe place, as you will need this if you have to send your motherboard back to the manufacturer to protect the socket during shipping. Your CPU is now installed into the motherboard.

CPU in place Protective plastic cover

CPU Cooler Installation

If you are using an Intel stock cooler (one which is bundled in the box with the CPU) remove it from the packaging and place the pins in the corners through the holes surrounding the CPU socket (ensuring that the pins at the corners are rotated to an unlocked position by rotating the top of them in the direction of the arrows). After this, turn the top of the pins in the opposite direction to that shown by the arrows to lock it in place. You can check that it is seated correctly by attempting to gently twist it - there should not be any significant movement. Be sure to arrange the fan cable so it doesn’t interfere with the spinning of the fan.

Applying stock cooler 1 Applying stock cooler 2 Applying stock cooler 3

Plug the 4pin PWM fan connector on the end of the wire coming from your CPU fan into the CPU_FAN header on your motherboard at this stage if you wish (we actually forgot about this until the build was already in the case). Watch that the cable isn’t in the way of the fan blade!

RAM Installation

As the final part of this sub-assembly we will be installing the RAM into the motherboard. Read the motherboard manual to find out which slots you should be using for the number of sticks of RAM you have (they are usually color coded and so can be easily referenced). We will be populating all the slots in our build. First, pull back the clips on either side of the RAM slots you are going to use

Pulling back DIMM slot clips

Notice the clear off-centre notch at a point both on the slot and the RAM stick to indicate which way round the sticks should be placed and ensure they can only be placed one way

Clearly Notched RAM

Place each RAM stick in a slot and push down evenly on both sides until the clips engage

Inserting the RAM Pushing the RAM into the slot Pushing the RAM into the slot 2
At this point in the build, if you have integrated graphics you can attempt to power on the build outside of the case by connecting the power supply 20/20/24 pin ATX and 4/8pin EPS connectors and shorting out the PW_SWITCH pins on the front panel headers by touching a conductive screwdriver or paperclip to them for a split second or connecting the actual case switch to power the build on.

Installing the Motherboard in the Case

We can now move this sub-assembly into the case


Best part about having a side panel window is peeling this off

Mmmmmmmm peeling this stuff off

Take off the case side panels

Taking off side panels Naked case

Find the box containing your screws and other accessories which are bundled with the case (it is usually located in a 3.5" drive bay) and find the standoffs for your case. These sit between your motherboard and the screw in order to stop the motherboard touching and shorting out on the case and are vitally important. In our case, the standoffs were pre-installed for an ATX motherboard. It is a relatively painless process, if they are not, to go through screwing the standoffs into the case in the locations where your motherboard has a matching hole for a screw.

Accessories box What's inside the box?

Next we need to install the motherboard I/O shield. This is a metal panel which covers the gaps between your motherboard I/O connectors in the cutout at the back of the case. Ensure this is the correct way round (engraved labels facing to the outside of the case and the right way up to match the connectors on the motherboard). This is a time when a lot of builders make their blood sacrifice to their machine on sharp edges, so take care! Place the metal panel into the gap at the back of the case and push firmly around the corners and outside edges until it clicks to secure it.

Motherboard i/o shield Installation of the i/o shield

Now with standoffs in position and I/O panel placed we can take our motherboard and place it in the case. It is best to lie the case on its side as you do this.

Lower the motherboard into place. Line up the connectors with the gaps in the I/O panel and push the connectors into the panel before lowering it all the way onto the standoffs. You may need to apply some pressure in the direction of the back of the case to line up the screw holes with the standoffs - this is normal and is the I/O panel resisting the connectors. However be sure that none of the metal tabs from the panel are making contact with the inside of the connectors after the process.

Lowering motherboard into the case Lining up with the shield Pushing the motherboard into place

Find the motherboard screws which were supplied with your case (these usually have a built in washer) and screw them into the standoff, thus securing the motherboard to the case.

Finding screw holes Screwing in the motherboard Screwing in the motherboard 2

Getting a Start on Cabling

Here's the connection of the 4pin connector to the CPU header we left till now!

Plugging in the CPU fan connector

While you're connecting fans, you can connect any 3 pin fan headers from case fans to 3 or 4 pin fan headers on the motherboard. See the motherboard manual if you can't find their location.

Plugging in the CPU fan connector

Start as you mean to go on with cable management! With a first build it can be tempting to not bother to manage cables and that you will 'sort it out another time' but that way it takes more work later or never gets done - it's very satisfying to have a neat build afterwards, and you can be much more proud of any pictures you show off. It also ensures that cables do not get in the way, gather dust or obstruct airflow. Here we secure the excess cabling of our rear fan with a cable tie.

Plugging in the a chassis fan connector Plugging in the a chassis fan connector 2

Adding a Graphics Card

Next we can move on to the installation of the graphics card. Remove the PCIe blanking plates corresponding to the slot you will be placing your graphics card in. Again, your motherboard manual will assist you in making a decision about which slot to use, but usually you should use the topmost PCIe x16 slot for your graphics card which more often than not lines up with the second PCIe slot blanking plate (and you will need to take off another below when you are using a usual dual slot graphics card)

Unscrewing the blanking slot covers Unscrewing the blanking slot covers 2

Press back the clip at the edge of the slot similarly to the RAM slots ready for you to insert the graphics card

Releasing PCIe clip

Lower the card into position and push down evenly at both ends until the clip engages.

Placing card in slot Placed card in slot

Screw the graphics card in to secure it in place - the graphics card will have holes in it similarly to those on the blanking plates allowing you to replace the screws which were originally there. We now have all the major components of the build installed

Screwing in the card

More Cabling - Case Cables

Now things get more fiddly as we begin cabling. Our preferred technique is to first sort out front panel connections before moving on to installing the power supply within the case to keep clutter to a minimum

Case connections

First we will focus on the front panel header connections which will be separate very small wires such as these, with labels on each for switches and LEDs

Front panel connections

Pass them through a case cutout as close to the headers as possible (the front panel header is usually along the bottom row) to the front of the build (we will be hiding cables as much as possible behind the motherboard tray where they are out of sight and do not disrupt airflow)

Cable management of front panel connections

We will now be connecting up these cables to the motherboard. This is an area where the motherboard manual is essential as each motherboard has a different arrangement of pins on their front panel header (which is why all the cables are separate rather than being bundled into one larger connector). Some motherboards come with an intermediary connector which does just this, making the job of cabling this header up easier. Double check your positives and negatives on LED connections.

Motherboard manual Motherboard manual 2 Connecting the front panel connections

After this tedious job is over you will be pleased to know that all the other cables are relatively simple. If your case has front panel audio connections the next job will be connecting the 'HD Audio' connector to the respective header on the motherboard. This header is, similarly, usually located along the bottom row of the motherboard. Your case may also include an AC97 connector which is legacy and does not need to be connected if a HD Audio connector is present.

Connecting HD Audio Connecting HD Audio 2

Finally front panel USB 3.0 will be a large connector which is easily distinguishable with two cables coming out of it. Connect this to the header on the motherboard being careful to align the notch carefully so as to plug it in the correct way round.

USB 3.0 cable Connecting the USB 3.0 cable Connecting the USB 3.0 cable 2

With all the case connections dealt with we can now focus on a small amount of cable management before proceeding. For now, just make use of cable ties to group cables together and pull the excess behind the motherboard tray leaving as little cable as possible showing from the front.

Cable typing front panel Finished job

Installing the Power Supply

Next we will be inserting the power supply. This simply slides into place underneath the motherboard and will sit against the back of the case. Which way up you place the fan really is up to you and what you prefer aesthetically - if you have a case with dust filters at the bottom and your PC is going to be sitting on a hard surface you should consider placing the fan facing downwards to isolate it from the rest of your case airflow. However it is equally valid to place the PSU with the fan facing upwards and this is preferred if your build will be sitting on carpet.

PSU Install PSU Install 2

The PSU is secured with 4 screws which are supplied with your case in each corner

Screwing in the PSU

Sorting out Power Cabling

First take all the connectors straight through the large cutout in the case to the rear of the motherboard tray and pull through all the excess

PSU cables

Place the 20/24pin ATX power cable and the 4 or 8pin EPS power cable (which is commonly labelled 'CPU Power') back through the cutouts closest to their headers. The EPS power connector will be at the top of your motherboard and 20/24pin cable along the edge. In most cases there is a cutout in the upper left corner of the motherboard to route the 4 or 8pin EPS power cable through in order to reduce cable clutter which you should use, however in our case this was not possible.

24 and 8 pin cables Placing through holes in the motherboard tray

Connect the 4 or 8pin EPS power connector to the CPU power connector on the motherboard. This is notched so will only fit one way. Pull any excess cable behind the motherboard tray.

Connecting the CPU power

Connect the large 20/24pin cable to its header on the motherboard. You can see which way this connects due to the clip and latch and it is once again notched to ensure it can only be connected one way. Once again keep the excess behind the motherboard tray.

Connecting the 24pin power cable

Route any required PCIe connectors for your graphics card through the motherboard backplate cutout closest to the graphics card. All PCIe power connectors on the graphics card must be filled by a cable in order to successfully power the card. 8 pin PCIe power connectors from the PSU are often designed to split into 6 pin and a 2 pin optional part - feel free to use just the 6 pin part if you have a graphics card with a 6 pin connector you need to fill.

PCIe power cable Placing PCIe cables through holes in the motherboard tray

Insert these cables into the graphics card PCIe connectors which will be located at the side or end of the card.

Powering the GPU Powering the GPU 2

After this the build is complete and should POST to an error telling you that you have no boot drives connected, if you wish to test it at this point! Don't forget the power switch on the power supply itself and to double check all the above connections if your build shows no signs of life at all.

Drive Installation

Next you can secure any drives you have to the caddies inside your case. We will simply be installing a single SSD and our case has tool-less drive mounting so we simply slot it into position. Other cases may require inserting drives into caddies using screws or other mechanisms and details of this will be listed in your case manual. SSDs, having no moving parts, can theoretically be placed anywhere in the build including screwed to the back of the motherboard tray to reduce clutter. HDDs will require a proper mounting solution to minimise vibrations.

Our SSD Our SSD placement

Drives, including optical drives in the 5.25" bay, require two connectors - SATA data and SATA power. Both connectors are "L" shaped so you can take a look before connecting it to see the correct orientation. SATA power can require a moderate amount of pressure to plug into stiff connectors.

First connect one end of the SATA data cable which will be supplied with your motherboard and/or drive to the drive, and the other to a SATA port on the motherboard. It will usually connect with a satisfying click as the clip engages. You should try to connect to SATA 6gbps (SATA 3) connections on the motherboard when using SSDs to ensure maximum speeds however this will not affect the speed of hard drives and will not impact the real world performance of an SSD significantly if you connect them to SATA 3gbps (SATA 2) interface.

SATA data cable Connecting the SATA data cable

Next, take a SATA power cable from your PSU and connect it to the SATA power connector on the drive (next to SATA data).

SATA power cable Connecting the SATA data cable

Finishing Up

Now you are completely finished with building. Only problem is a lot of excess cabling at the rear side of the motherboard tray. Use cable tie points on the case to secure cables out of sight and route them in a channel along the edge of the tray.

Cable management Cable management 2 Cable management 3 Finished back of build

After this you can place the front and back panels back on the PC and you are ready to go! Enjoy your brand new PC and we hope your experience was a positive one.

Replacing rear side panel Replacing front side panel Finished front of build All done!

Have fun building, and thanks for reading!