A. XP Home Edition and XP Professional are available in full and upgrade versions. If you're upgrading from a qualifying OS, you can purchase the less-expensive upgrade version; otherwise, you need to purchase the full version. However, even if you purchase the full version, XP doesn't support all upgrade paths. Review the following table to determine whether XP supports your upgrade path:

Current Version Windows XP Home Windows XP Pro
Windows 3.1 or Windows 95 No No
Any server version of Windows No No
Windows 98/98 SE Yes Yes
Windows Me Yes Yes
Windows NT 3.51 No No (you need to upgrade to NT 4.0 orWin2K first)
Windows NT 4.0 No Yes
Windows 2000 Professional No Yes
Windows XP Home Edition   Yes
Windows XP Professional No