Memory

Every computer comes with a certain amount of physical memory, usually referred to as main memory or RAM (random-access memory). Computers store currently running applications and data in this area. To find out how much memory you'll need, take into account your operating system and the applications that you plan to use. A general rule of thumb: You'll want 512MB for Windows XP or Mac OS X and 256MB for all other Windows and Mac operating systems. If you hope to run Windows Vista when it's released in January 30, you'll need at least 512MB, preferably 1GB.

If you're planning to hang on to your notebook for a long time, look for a laptop with easy-to-access memory slots, as memory is typically one of the first specs you'll want to upgrade.