How To Upgrade To A New PC Case

So you’ve found a sweet new case for your PC, brimming with LEDs and fan cutouts and acrylic windows all over. Now you’ve just got to get all the guts from your current PC inside of it. Here’s how.

Be warned, this is an involved process: you have to go through more or less all of the steps of building a new PC from the ground up, with the added inconvenience of having to disassemble another one first. It’s time-consuming and boring, but not particularly difficult. Also, we’re not covering liquid-cooled computers here. The setup on those is very specific to the components your computer uses, and also can be pretty finicky. If you have a liquid-cooled PC, you’ll need to find instructions specific to your setup or, better yet, get some help from someone who’s done it before.

And as always, if you’ve never done this before, we recommend taking pictures of how things are set up as you disassemble your PC—where cables are plugged in, where components go, and so on.

What You’ll Need

All you really need to work on a modern PC is a Philips-head screwdriver. I recommend using two, a big one for leverage and a small one for the hard-to-reach crannies in your case. If you’re working in a particularly static-prone environment, you might also want an anti-static bracelet. Finally, a few cups or bowls can be really helpful to keep your various screws from rolling away.

I’ll be using my personal desktop for this demonstration. It’s built into a Fractal Design R4 case, a fairly typical ATX Mid Tower size. If you’re using a gaming PC, it will probably look pretty similar, unless you’re specifically building something much smaller (like a Mini-ITX build) or more elaborate. Even so, the rough steps will be broadly the same even if your build is very different.

Setting Up

First, and obviously, remove all the various power and data cables from your PC, and then set it on a table or desk in a bright space. Use some place without carpet if you can, to avoid static electricity.

The first thing you’ll need to do to begin tearing apart your machine is to maximize your access to all the components. On an ATX tower, this means removing the access panels from both sides of the case (some cases might have a single cover that pulls off as one unit rather than separate access panels). They’re held in place with screws (sometimes, thumbscrews) on the rear panel. There are generally two or three on each side. Take these out and set them aside.

Then simply slide the access panels towards the back of the machine and pull them off. Set them aside.

With these major access barriers removed, you’ll have easy entry to every component.

If your case has any more externally-removable parts, like dust filters, go ahead and pull these out as well.

Before you begin to actually remove components, it’s best to decide on a general order. This depends on your exact setup and your proclivities, but I prefer to remove the power supply first, since it’s connected to almost everything else. Getting it (and particularly it’s many cables) out of the way will make the rest of the job go easier. In some cases, you might not be able to pull the power supply out without first removing other components—like a CPU cooler. That’s fine. Do things in whatever order feels best to you.

Removing the Power Supply

To begin removing the PSU, you’ll need to unplug it from all the components that are using it. On my machine, this includes all of the following:

  • Motherboard (24-pin primary rail)
  • Motherboard (8-pin processor rail—yours may be bigger or smaller)
  • Graphics card (8-pin—yours may be bigger or smaller)
  • Hard drive and SSD (SATA power cables)
  • DVD drive (SATA power cable)
  • Case fans (various)

It’s probably easiest to keep your case vertical for this and most of the rest of the steps (except the motherboard).

If you have a modular power supply, which allows you to remove cables from both the components and the power supply itself, this is even easier. You can tug on either end of the cable to free it. (Note: most pre-built desktops do not use a modular power supply.)

Now your power supply should be mostly clear. If it’s not modular, position all the cables as out of the way as you can in preparation for removing the unit itself.

Now move to the back of the case. There are a few screws affixing the power supply to the back of the frame. (On some case designs, these retention screws might be on the top or bottom.) Remove them and set them aside.

With the retention screws released, the power supply is loose, and you can pull it out of the case.

Set it aside and move on to the next components.

Removing Hard Drives and Disc Drives

Older case designs retain their hard drives, SSDs, and disc drives with only screws in the frame. Newer and more advanced ones use “sleds” or “caddies,” screwing the drives into these easy in-out gadgets and then sliding them into place for easy swaps. The hard drive and SSD in my PC use this method, while the DVD drive is screwed down tight. We’ll start with the former.

First, unplug the SATA data cables from your hard drive and from the motherboard on the other end.

With both the power and data cables removed from my drives, I can pull the caddies out of the case’s frame.

Now for the DVD drive. Start by removing the SATA data cable. Since the drive itself is screwed into the frame, I’ll have to remove the screws from both sides before it comes out.

With the power cable, data cable, and retention screws removed, I can pull the drive out of the front of the case. You might want to nudge it a bit from the back, but pull it out from the front, since you’ll have limited space in the opposite direction.

Set your drives aside. If they’re screwed into sliders or caddies, unscrew them to prepare them for re-installation later.

Move on to the next component.

Removing the Graphics Card

Obviously, this part of the guide doesn’t really apply if you don’t have a discrete graphics card in your computer. I do, so let’s get it off of the motherboard to make the final steps of disassembly easier.

First, remove the power cable that went to the power supply if you haven’t already done so. Then take out the screw retaining the GPU to the back of the case, where the adapter plugs stick out. It’s probably a thumbscrew. If your card is a double-width, you’ll need to remove both screws.

Now, press the plastic tab at the end of the PCI Express card slot that the graphics card is plugged into. It should “snap” down into place on the motherboard, releasing the graphics card.

With the retention screws removed and the plastic tab pressed down, grip the card firmly and pull. It should come free of the motherboard.

Set the graphics card aside and move to the next part. If you have any other hardware that’s occupying your PCI-Express slots, like a Wi-Fi or sound card, take them out in the same way.

Remove The Case Fans

The fans attached to your case are there to suck in cool air and blow out hot air. You’ll want to get them out before the motherboard and remaining components. Luckily this is one of the easier processes. And honestly, you might not need to remove the fans themselves from the case if your new case already has fans attached.

First, if any of your case fans were plugged into ports on the motherboard (instead of the power supply), unplug them now. Those 3- or 4-pin connections look like this:

Now, switch to the outside of the case and simply remove the screws holding the fans in place. Make sure to hang on to the fan from the other side as you remove the last screw, to keep it from falling in.

Repeat this step for all your case fans. If your case has removable brackets for fans, just take them out in the same way.

Removing the Motherboard

We’re going to keep the RAM, CPU, and CPU cooler attached to the motherboard, because they’re generally light enough to come with it (and an extra step you don’t need for most cases). If you have a more elaborate CPU cooler or a water-based cooler, you may need to take it out to access some of the screws holding the motherboard in place.

First, set your case on its side, with the motherboard facing up. Then remove any other cables plugged into your motherboard. At this point, these should mostly be control, audio, and USB cables running directly from your case.

Keep an eye on the I/O pins at the bottom-right corner of the motherboard. These are very tricky, and have to be connected in a particular order for your case’s power button, reset button, hard drive indicator, and power indicator to work. Unless you really like staring at tiny type or tracking down your motherboard’s user manual, it’s a good idea to take a photo of where everything is before taking it out, so it’ll be that much easier when you move everything to the new case.

Now, remove the screws that are attaching the motherboard to the case’s risers. These can be hard to spot, especially if you have dark screws on a dark PCB, like mine. Generally there are four positioned near the corners, with two to four more somewhere in the middle for stability.

With all the motherboard screws removed, grasp the motherboard carefully and pull it forward slightly, to get it clear of the I/O plate (the little steel rectangle with cutouts for the ports on the back of the case). Then lift it clear of the case and set it aside. If the motherboard does not lift away easily, it likely means you missed a screw. Go back and check again.

Then the final step is to push the I/O plate itself into the case slightly and pull it out.

Now you should have all your components free of the old case, and ready to install into the new one. For this article, we’ll just be re-using the original case, since I don’t have a spare handy. And besides, once I blow five years’ worth of dust out of it and clean all the components, it’ll be practically new anyway.

Installing Components in Your New Case

For the new case, we’re essentially going to go in reverse. You’ll be working with all the same components, just putting them in instead of taking them out. Remove both the access panels of the new case, and get started.

Installing the Motherboard

If they’re not already installed, screw down the motherboard risers that came with your new case. These allow you to screw down the motherboard and keep its electrical contacts from shorting out on the metal of the case itself. Note that some cases may have different positions available for these risers, but they should still match up to available holes in the motherboard.

Now install the I/O plate. This is the same one that you took from your previous case. Just check that it’s aligned properly with you motherboard’s rear-facing ports, and push it into place from inside the case towards the outside, on the back. It’s possible the new case already has one in place. If so, you may need to remove it to insert the one that matches the ports on your motherboard.

Move the motherboard onto the risers, aligned with the screw holes. It may take a little gentle wiggling get the ports on the back of the board pushed into their respective holes in the I/O plate—just go gently and make sure you have clean access to all the ports on the rear of the computer.

Now screw down the motherboard screws in the same spots you placed the risers. Make sure they’re firmly in place, but don’t screw down too far once you feel resistance—you might crack the circuit board.

Installing Case Connections

Now re-connect all the case connections to your motherboard. On a modern case, these are cables for the power switch, reset switch, power lights, and hard drive indicator light. Consult your motherboard manual, or the photo you took previously to get these connections right.

Your case also probably has an HD Audio cable and a USB 3.0 cable, and may have other USB cables as well going to the motherboard. These are usually marked clearly on the motherboard’s PCB.

As you’re routing the cables around, here and all throughout the reassembly, try to leave as few loose as you can. The rear of the case is a good place to “hide” excess cable length, as long as it’s not too thick to allow the rear access panel back on.

Installing the Case Fans

Your new case may have come with some fans pre-installed. If it did, plug them into the three- or four-pin plugs on the motherboard (marked “fan” or something similar). If not, install the ones you removed from your previous case. Simply screw them down from the outside.

The side of the fan with the plastic blocking the blades is the output—air flows in the direction of the plastic. Intake fans (with the plastic facing in) go on the front, output generally go on the rear, top, or bottom. Check out this guide if you’re confused about proper airflow management inside your case.

If your fans can connect to your motherboard, connect them now. Ditto if they can connect to your case and it has an on-board controller.

Installing the Graphics Card

Again, if you don’t have a discrete graphics card, skip this section. If you do, begin by removing the PCI-E spacers for the PCI-Express slot you’re going to use, but hang onto the screws. To decide which one is right if you don’t know, check out this guide—it’s generally the one closest to the processor area.

Then slide the card down into the slot, putting pressure on the side nearest the rear of the case first. Make sure it aligns with the exterior so that you can plug in the monitor cables.

Push down firmly. When you see this plastic tab wiggle, you’re just about there. Pull the tab on the slot up until it “locks” down onto the card. Note that some motherboards include different types of tabs. Some automatically lock when you insert the card, some push in from the side.

Now re-install the screws to permanently affix the card in place.

Installing the Storage Drives and Disc Drives

Again, you’re just going in reverse here. Place your drives into their appropriate bays, either screwed in directly or attached to their caddies. (You’ll need the caddies that came with your new case, not the ones you removed from the old case.)

Then plug the SATA data cables into the rear of the drives and attach them to the motherboard’s SATA drives. You want to install them in the same order on the board (port 1, 2, 3, et cetera) to avoid boot issues.

Installing the Power Supply

Now for the most complex part: installing the power supply. Start by inserting it into the PSU bay in the new case, then screwing it into the back with the power cord facing outward.

You generally want to direct the power supply’s built-in fan directly out of the case, away from the internal components, since it will be blowing hot air constantly.

Now route all the power cables to your necessary components.

  • 24-pin main power rail for the motherboard
  • 4/6/8-pin power rail for the motherboard’s CPU socket
  • SATA power rail to the hard drive and any other drives
  • 6/8/12-pin power rail to the graphics card (if you have one)
  • Additional power for more case fans and other accessories if necessary

If you’re not sure where some go, take a look at the pictures you took, or consult your motherboard’s manual.

Make sure the connections are tight, and try to route as much of the cabling as you can behind the motherboard tray to keep everything tidy. Much tidier than my example, if you can, which shouldn’t be all that difficult.

Cable management is about more than just keeping things looking pretty inside your case. Getting cables out of the way ensures that air flow in the case is not impeded, and also that you can more easily get to components when you need to.

Closing Up and Booting

You’re nearly done. Give everything another once-over, paying particular attention to your fans—it’s easy for a loose cable to drag on one, and if it does, you’ll need to open the PC up again and find the error.

If you’re sure you’ve covered everything, place the access panels back on the left and right sides, and then place the thumb screws in and batten down the hatches. Install any accessories for the case, like dust filters.

Move your shiny new case and your dusty old parts back to your computer desk. Plug everything in and start up. If it doesn’t boot directly into Windows, don’t panic—you might just need to go into the UEFI (also known as the BIOS) and set the correct boot order for your drives.

If you’re still having problems, open up the PC again and check your connections. Common problems are mixed-up SATA cables, forgetting to connect the CPU power rail, and (yes, really) forgetting to switch the power supply on.

Image credit: Fractal Design, Dell 

Michael Crider has been covering technology on the web since 2011. His interests include folk music, football, science fiction, and salsa verde, in no particular order. He wrote a novel called Good Intentions: A Supervillain Story, and it's available on Amazon. You can follow him on Twitter if you want.