Some stuff in simplified terms: The general belief in the tech world is ME is the worst version of Windows since 3.0. Of all the 9x based Windows, 98SE is the most stable. The list prices for XP upgrades are $99 for Home; $199 for Pro. XP Pro is a direct decendant of NT Server. XP Home is a direct descendant of NT Workstation. XP Home does not support multiple processors; XP Pro does.