How to Install RAM in a Laptop or Desktop: Step-by-Step Guide

Adding RAM is one of the cheapest ways to make a laptop or desktop feel quicker, and on most business machines it takes about ten minutes with a small screwdriver. The work itself is simple. The part that trips people up is buying the right module and checking that the machine has a free slot before the parts arrive.

Key takeaways

• Laptops use small SO-DIMM modules and desktops use full-size DIMMs. They are not interchangeable.
• DDR4 and DDR5 have different notches, so a module of the wrong generation will not fit.
• Task Manager shows how many memory slots you have and how many are in use.
• Matched pairs run in dual channel, which helps everyday speed and integrated graphics.
• Some slim laptops have memory soldered to the board and cannot be upgraded.

Step 1: Check what your computer takes

Open Task Manager with Ctrl + Shift + Esc, choose Performance, then Memory. The panel shows the speed, the form factor and a line such as Slots used: 1 of 2. If every slot is full, you will need to replace a module with a larger one rather than add another.

Next, confirm the memory type. The exact model number, found on the sticker underneath a laptop or on the side of a desktop, tells you the generation in the manufacturer’s specifications. Free tools such as CPU-Z also show the type and speed of the modules already fitted.

Step 2: Buy the right module

• Match the generation (DDR4 or DDR5) and the form factor (SO-DIMM or DIMM).
• Match the speed of the existing module where you can. Mixed speeds work, but everything runs at the slower speed.
• For dual channel, fit two modules of the same size, such as 2 x 8GB rather than one 16GB.
• Check the maximum memory your model supports in its specifications before buying large modules.

Not sure how much to add? Our guide to how much RAM you need in a laptop sets out when 8GB, 16GB and 32GB make sense, and you can see what is currently in stock in our refurbished memory section.

Step 3: Prepare safely

1. Save your work and shut the computer down fully, not sleep or hibernate.
2. Unplug the charger or power cable, and any docks or USB devices.
3. On a laptop with a removable battery, take the battery out. If the battery is internal, follow the service manual for your model, which often says to disconnect it first.
4. Work on a hard table, and touch a bare metal surface to discharge static before handling the module.
5. Hold memory by its edges and avoid touching the gold contacts.

Step 4: Install RAM in a laptop

1. Remove the screws on the base cover or memory door. Keep them in a cup, because they are often different lengths.
2. Lift the cover gently with a plastic pry tool, starting from a corner. Do not force it.
3. To remove an old module, push the two side clips outward and it will pop up at an angle.
4. Line up the notch on the new module with the key in the slot, then insert it at about 30 degrees, firmly, until the contacts disappear into the slot.
5. Press the module down flat until both clips click into place.
6. Refit the cover and screws before switching on.

Step 5: Install RAM in a desktop

1. Lay the tower on its side and remove the side panel.
2. Find the memory slots next to the processor cooler. The motherboard manual shows which slots to use first for dual channel, often slots 2 and 4.
3. Open the clips at the ends of the slot.
4. Line up the notch, then press straight down on both ends of the module until the clips snap closed. This takes more force than most people expect.
5. Refit the panel, reconnect the power and switch on.

Step 6: Check that it worked

The first start after a memory change can take a little longer than usual while the system checks the new modules. Once Windows loads, open Settings, then System, then About, and look at Installed RAM. Task Manager should also show the new total and the slots in use.

If the computer will not start

When an upgrade is not the answer

If your laptop has all its memory soldered, or it still runs a mechanical hard drive with an older processor, more RAM will not fix the bigger problem. In that case a newer machine is often better value. Our refurbished laptops are tested business models, many already fitted with 16GB, and the refurbished computers range has desktops with free slots for later upgrades. If the machine also feels slow at start-up, read whether an SSD upgrade is worth it.

Frequently asked questions

Can I mix different RAM sizes?

Yes. A 4GB and an 8GB module will work together, but only part of the memory runs in dual channel. Matched pairs give the best performance.

Can I put desktop RAM in a laptop?

No. Laptops use smaller SO-DIMM modules and desktops use full-length DIMMs, and the slots are physically different.

Do I need to change any settings after installing RAM?

Usually not. Windows detects the new memory automatically. If the total is wrong, check the module is seated and that the BIOS shows the full amount.

Will upgrading RAM affect my warranty?

Fitting memory in a user-accessible slot is normally fine, but terms vary. If your machine is under warranty with us, ask us first and we can fit it for you.

Most RAM upgrades come down to three checks: the right type, a free slot and a module pressed in until it clicks. Get those right and an older machine can feel noticeably quicker for very little money.