Most laptops have a small "door" (about 4"x4") on the bottom, held by a couple of screws. You have two slots accepting a max of 512 meg of memory. The computer comes "native" with 128 meg, so you may have two 128 sticks or one 256 meg. If you do have two 128's, you"ll have to order two 256's for 512 meg (or one 256 for a total of 384 meg).