Additional RAM improves laptop performance by decreasing the number of times the operating system reads and writes data to the hard drive in the form of virtual memory. Additional RAM also helps the operating system to run multiple applications more efficiently.

The make and model of the laptop determines the type of RAM chip needed. It is important to select the memory type that is physically compatible with the laptop. Most desktop computers use memory that fits into a DIMM slot. Most laptops use a smaller profile memory chip that is called SODIMM. SODIMM has 72-pin and 100-pin configurations for support of 32-bit transfers and 144-pin, 200-pin, and 204-pin configurations for support of 64-bit transfers.

NOTE: SODIMMs can be further classified as DDR, DDR2, and DDR3. Different laptop models require different types of SODIMMs.

Before purchasing and installing additional RAM, consult the laptop documentation or the website of the manufacturer for form-factor specifications. Use the documentation to find where to install RAM on the laptop. On most laptops, RAM is inserted into slots behind a cover on the underside of the case, as shown in Figure 1. On some laptops, the keyboard must be removed to access the RAM slots.

Consult the manufacturer of the laptop to confirm the maximum amount of RAM each slot can support. You can view the currently installed amount of RAM in the POST screen, BIOS, or System Properties window.

Figure 2 shows where the amount of RAM is displayed in the System utility.

In Windows 7 and Windows Vista, use the following path:

Start > Control Panel > System

In Windows XP, use the following path:

Start > Control Panel > System > General Tab

To replace or add memory, determine if the laptop has available slots and that it supports the quantity and type of memory to be added. In some instances, there are no available slots for the new SODIMM. To remove the existing SODIMM, follow these steps:

Step 1. Remove the AC adapter and battery from the laptop, along with any other components designated by the manufacturer.

Step 2. Remove the screws on the cover above the memory socket to expose the SODIMM.

Step 3. Press outward on the clips that hold the sides of the SODIMM.

Step 4. Lift up to loosen the SODIMM from the slot and remove the SODIMM.

To install a SODIMM, follow these steps:

Step 1. Align the notch of the SODIMM memory module at a 45-degree angle and gently press it into the socket.

Step 2. Gently press down on the memory module into the socket until the clips lock.

Step 3. Replace the cover and install the screws.

Step 4. Insert the battery and connect the AC adapter. Turn the computer on and access the System utility to ensure that the RAM has been installed successfully.