What You Need Before You Start

Building a PC means assembling a computer from individual parts instead of buying a finished machine. You will install a processor, memory, storage, power supply, and other components into a case. The process takes two to four hours for a first-time builder and requires only a screwdriver and basic care to avoid static electricity damage.

Before you open any boxes, gather your parts in one place and check that everything arrived. Lay out a workspace with good lighting — a desk or table works fine. Wear an anti-static wrist strap (a cheap band that clips to your case and grounds you) or touch a metal part of the case frequently to discharge static. Have your motherboard manual nearby; it shows exactly where each part connects.

The parts you will install are the motherboard (the main circuit board), CPU (processor), RAM (memory), storage drive, power supply, and case fans. Some builds also include a graphics card for gaming or video work. Each part plugs into a specific slot or socket, and the manual shows you where.

Key Takeaways

  • Install the CPU into the motherboard socket first, then add RAM sticks and the M.2 storage drive while the motherboard is outside the case.
  • Mount the motherboard into the case using brass standoffs (small spacers that prevent the board from touching the metal case), then install the power supply at the bottom.
  • Connect the 24-pin power cable to the motherboard and the 8-pin cable to the CPU socket, then plug in any graphics card and storage drives.
  • Flip the power supply switch on, press the case power button, and watch for lights and fan movement to confirm the build works before installing an operating system.
  • Your motherboard manual is the most important tool — it labels every socket and connector, so you do not have to guess where parts go.

Install the CPU and RAM While the Motherboard Is Outside the Case

Start with the motherboard on a clean, flat surface. Locate the CPU socket (a large square with a hinged retention arm) and lift the arm all the way up. The CPU has a notch or arrow on one corner that matches a notch in the socket — align these and gently place the CPU into the socket without forcing it. Lower the retention arm to lock it in place. The CPU should sit flush with no gaps.

Next, install RAM sticks into the long slots next to the CPU. Open the clips at both ends of each RAM slot, line up the notch in the stick with the key in the slot, and press down firmly until both clips snap closed. RAM requires real pressure — do not be afraid to push. Most builds use two or four RAM sticks, and they click in with a satisfying snap when seated correctly.

If your build includes an M.2 storage drive (a small rectangular stick), locate the M.2 slot on the motherboard (usually near the CPU) and insert the drive at a 30-degree angle, then press down and secure it with the small screw provided. This step is optional if you are using a 2.5-inch SSD or hard drive instead, which you will install later in the case.

Mount the Motherboard and Power Supply Into the Case

Before placing the motherboard in the case, install brass standoffs into the case at the holes that match your motherboard's mounting holes. Standoffs are small cylindrical spacers that prevent the motherboard from touching the metal case and causing a short circuit. Screw them in by hand or with a screwdriver — they should be snug but not over-tightened.

Carefully lower the motherboard into the case and align the mounting holes with the standoffs. Screw the motherboard down using the small screws provided, working in a cross pattern (like tightening a car wheel) to keep pressure even. Do not over-tighten; snug is enough.

The power supply goes at the bottom rear of the case, usually in a separate compartment. Slide it in with the fan facing down (if your case has ventilation holes in the bottom) or up (if it does not). Align the mounting holes and screw it down with the four screws provided. Leave the power supply switched off for now.

Connect Power Cables to the Motherboard and CPU

The power supply has thick cables bundled together. Find the large 24-pin connector (labeled ATX 24-pin on the power supply) and plug it into the matching socket on the motherboard, usually on the right edge. It only fits one way, so align the notch and push until it clicks.

Next, find the 8-pin CPU power connector (sometimes labeled CPU 8-pin or EPS 8-pin) and plug it into the socket near the CPU, usually at the top left of the motherboard. This cable delivers power directly to the processor. Again, it only fits one way.

If your build includes a graphics card, locate the PCIe slot (a long horizontal slot, usually the topmost one) and remove the metal bracket from the rear of the case that covers it. Insert the graphics card into the slot with a firm, even push until it clicks at both ends. Secure the card to the case bracket with one screw. Then plug the 6-pin or 8-pin power connector from the power supply into the card if it has one.

Install Storage Drives and Connect Them

If you are using a 2.5-inch SSD or a 3.5-inch hard drive, mount it in a drive bay using the four screws provided, or use a mounting bracket if your case requires one. Most modern cases have a dedicated SSD bracket on the back of the motherboard tray.

Connect a SATA data cable from the motherboard to the drive (the thin flat cable with a notched connector). Then connect a SATA power cable from the power supply to the drive (the wider flat cable). If you installed an M.2 drive earlier, you do not need to do anything else for it — it draws power directly from the motherboard.

Route cables behind the motherboard tray or through cable management holes to keep them out of the way of fans. This improves airflow and makes the build look cleaner, though it is not required for the PC to work.

Install Case Fans and Check Connections

Most cases come with one or two fans already installed. If you are adding more, mount them using the four screws provided, making sure the fan blades face the right direction (intake fans pull air in, exhaust fans push air out). Connect fan power cables to the motherboard fan headers (small connectors labeled CPU_FAN, SYS_FAN, or similar on the motherboard).

Before closing the case, do a final check: verify that the 24-pin and 8-pin power cables are fully seated, that the CPU and RAM are locked in place, and that no cables are pinched under the motherboard. If you have a graphics card, make sure it is fully inserted and screwed down.

Power On and Test the Build

Close the case and flip the power supply switch to the on position. Press the case power button (usually on the front panel) and watch for lights and fan movement. The motherboard should light up, fans should spin, and you should hear the power supply running. If nothing happens, turn off the power supply immediately and check that the 24-pin and 8-pin cables are fully connected.

If the PC powers on, let it run for a minute, then turn it off. This first test confirms that the basic assembly is correct and that there are no short circuits. Do not worry if nothing appears on a monitor yet — you have not installed an operating system.

Once the PC powers on successfully, you can install Windows, Linux, or another operating system using a USB drive. The operating system installation process is separate from the hardware build and is covered in other guides.

Frequently Asked Questions

Do I need thermal paste for the CPU?

Most modern CPUs come with thermal paste already applied to the cooler, or the cooler comes with a tube of paste. If your cooler is bare, apply a small pea-sized dot of paste to the center of the CPU before mounting the cooler. The cooler spreads it evenly when you tighten it down.

What if the PC does not turn on?

The most common cause is a loose 24-pin or 8-pin power cable. Turn off the power supply, unplug the cables, and push them back in firmly until they click. Check that the CPU is fully seated in its socket and that the retention arm is locked. If it still does not work, remove the RAM and reseat it — sometimes a stick that looks installed is not fully clicked in.

Can I build a PC without an anti-static wrist strap?

Yes, but it increases the risk of static damage. Instead, touch a metal part of the case frequently to discharge static, work on a non-carpeted surface, and avoid wearing wool or synthetic clothing that builds up charge. A wrist strap costs under ten dollars and is the safest option.

How do I know if my parts are compatible?

The motherboard manual lists the CPU socket type, RAM type, and storage connections it supports. Match your CPU to the socket, your RAM to the type listed (DDR4 or DDR5), and your storage to the available slots (SATA or M.2). Most modern parts are compatible, but checking the manual prevents buying a CPU that does not fit your motherboard.

Do I need a graphics card?

Only if you plan to game or do video editing. Most CPUs have built-in graphics that work fine for everyday tasks like web browsing and office work. If your CPU has integrated graphics, you can skip the graphics card and use the video output on the motherboard instead.