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 Win XP Home Win XP Pro
Win 3.1/3.11 No No
Windows 95 No No
Windows 98/98SE Yes Yes
Windows ME Yes Yes
Windows NT 3.51 No No
Windows NT 4.0 No Yes
Windows 2000 Pro No Yes
Windows XP Home N/A Yes
Windows XP Pro No N/A