Do you need as much memory when you're running office applications as you do when you're gaming? How much memory do you need in Vista to game comfortably, and spreadsheet smoothly? Usually a hardware upgrade isn't required for a new operating system. Yet if you are planing to upgrade Microsoft Windows XP to Microsoft Windows Vista, it's almost impossible to avoid a PC overhaul. If the PC doesn't have enough RAM to satisfy Vista's intense thirst, you'll be the slowest thing on two wheels.