The first step is to know what kind of memory you need. There are several different types and not all can be used in all machines. Often, you can go to a memory website, like Crucial.com and enter in the type of computer you have. This will let you know what kind of memory your computer uses.

Once you have your memory, you need to install it. When handling the memory and touching the internal parts of the computer, make be careful of static electricity. One tip is to touch the the metal frame of the case before handling the parts.

On the motherboard, you'll see the memory slots near the processor. Take a look at the memory chip - you should see a small notch at one end of the metal contacts. This lines up with an extra piece of plastic in one end of the slot. Line up the chip with the slot and press it firmly into the slot without forcing it. It should slip in without any undue force. You may need to rock it a bit to get it to click in fully. Make sure the clips on either end are locked in.

Close up the case and power the system on. If the system boots up and shows the expanded memory, you're in business. If the system doesn't boot and beeps, or doesn't show the extra memory, shut the system down and check the memory again.