W2k, XP adn W2k3 are all very different OS's. W2k3 is a server OS for starters. It is not meant for and should not be used for a workstation OS. Xp is similar to W2k Pro but it does have many differences. They are all stable OS's and should not have to be reinstalled as often as you say you have to. If you are having to re-install that often then it is due to either the apps and or tweaks you are loading or hardware.