[My computer uses PC2700 (DDR333). Can I use PC3200 (DDR400)?]

DDR memory was designed to be backward compatible so generally speaking, you can safely add faster memory to your computer. For example, you can install a PC3200 DDR module in a computer that calls for PC2700 DDR. However, keep in mind that faster memory will not necessarily make your system faster. You can't speed up your computer by adding faster memory if other components in your computer (your processor or other memory modules) operate at a slower speed.