To get rid of Windows XP and reinstate the good old days, open the Add or Remove Programs program in your Control Panel. As shown in Figure A-6 at top, Windows XP is listed among the other programs currently installed in your machine.
Figure A-6. Whenever you perform an upgrade installation from Windows 98, Windows 98 SE, or Windows Me, you actually retain both the old and the new versions of Windows. If, as the months go by, you decide that you’d like to reclaim the disk space being used by the dormant operating system, you can delete it. You can delete Windows XP (top), restoring your older version, or you can delete the older version (bottom), committing to Windows XP forever.
Click Windows XP Uninstall, then the Change/Remove button, then Uninstall Windows XP. When you’re asked if you really want to uninstall Windows XP and restore your old operating system, click Yes. When the process is complete, your computer will shut itself down, restart, and then start up with your old copy of Windows 98, Windows 98 SE, or Windows Me.