This guide covers replaceable desktop DIMM memory. It does not apply to a laptop or a computer with soldered memory. The goal is to fit compatible modules and confirm the installed capacity afterwards.
Before you begin
Check the exact motherboard or computer manual for the supported memory generation, module capacity and recommended slots. DDR4 and DDR5 are not interchangeable. If you are using two modules in a four-slot board, the manual identifies the preferred pair of slots.
Prepare a clear, dry work area and keep the manual nearby. You may need a screwdriver to remove the case panel. Save your work, shut down the computer and unplug the power cable. Do not open a power supply unit.
- Confirm that the modules match the motherboard specification.
- Check the recommended slots in the manual.
- Shut down, switch off at the wall and unplug the computer.
Install the modules
- Remove the side panel according to the case instructions. Touch unpainted metal on the case to discharge static electricity, and avoid working on carpet. Hold each module by its edges, not its gold contacts.
- Find the memory slots beside the CPU. Release the slot latches as described by the motherboard manual. Some slots have a latch at only one end.
- Align the module's notch with the ridge in the slot. It fits one way only. If the notch does not line up, stop and recheck compatibility. Never force a different generation into the slot.
- Press evenly at both ends until the module seats fully and the latch or latches close. A partly seated module is a common reason for a failed first boot.
- Replace the panel, reconnect power and start the computer.
Confirm the result
Check the memory amount in the firmware setup or in the operating system. On Windows 11, follow How to check how much RAM is installed. The reported usable amount may be slightly lower than the installed amount because some hardware reserves memory.
If the computer does not start or the new capacity is missing, power it down, unplug it and recheck seating and slot order. Try the original modules alone to determine whether the new modules are involved. Consult the motherboard diagnostic lights or manual before repeating attempts. Stop if you smell burning, see damage, or a module or slot becomes unusually hot.
Reversing the change
Power down and unplug the computer again. Release the latches, remove the new modules by their edges and reinstall the original compatible modules in their previous slots. If the machine still does not boot with the original configuration, seek qualified repair help rather than continuing to swap parts under power.