Uninstalling Windows XP
To uninstall Windows XP from an upgraded system, navigate to the Add/Remove Programs applet in Control Panel, highlight Windows XP, and click the Change/Remove button.
You cannot uninstall Windows XP if you have converted your FAT partition to NTFS, or upgraded from Windows NT 4 Workstation or Windows 2000 Professional.
Programs that have been modified since the upgrade to Windows XP may not function properly after the un-installation, particularly if they hook into registry settings unique to Windows XP.
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