64-bit drawbacks: The biggest drawback is that there are many devices that do not yet have 64-bit drivers, and thus will not be able to be used in Vista 64-bit. For example, that Epson printer that you've loved to use for the last 3 years under a 32-bit operating system might not work at all under 64-bit. The same is true for any device -- you have to rely on the manufacturer to develop the drivers for you. So, before you consider whether or not to get a 64-bit copy of Vista, check the manufacturer websites for all your peripherials and hardware. Printers, TV tuners, game pads, wacomm tablets, and wireless internet cards are all major red flags for driver worries. In addition, very few programs are developed for a 64-bit environment, so very few programs will see any performance benefit by running under Vista 64-bit.

64-bit advantages: The biggest advantage of a 64-bit Operating system is that it enables Windows to manage a lot more memory. In previous 32-bit operating systems, with Windows trying to keep track of all the memory on your video card, your system RAM, etc, the limitations of 32-bit computing meant that Windows could only keep track of around 4gb of RAM total. With a 64-bit processor and operating system, Windows can keep track of significantly more memory, which is potentially a very important feature for high-end, RAM-thirsty applications. For the most part, it will be a long time before the typical home user needs to access more RAM than a 32-bit operating system allows, but servers and video editing workstations (or other computers needing more than 4GB of memory) can benefit from the higher memory limits of a 64-bit platform.