Tests and Scans
Windows XP supports upgrades from Windows 98, Windows Millenium Edition, Windows NT, and Windows 2000. Each of those operating systems can be upgraded to Windows XP Professional.
You can also opt to upgrade to Windows XP Home Edition from any of those operating systems, except Windows 2000 or NT. Upgrading will preserve your applications and most Windows preferences.
Windows XP does not support an upgrade from Windows 95. Windows 95 users whose hardware meets minimum XP requirements will have to perform a clean install of a full version of XP Home Edition or Professional. That means they will have to reformat the hard drive and reinstall all applications.