Final answer:
Windows XP mode is a free download for Windows 7 Professional, Enterprise, and Ultimate editions, allowing for compatibility with older applications designed for Windows XP.
Step-by-step explanation:
Windows XP mode was a feature provided by Microsoft to help users run older software incompatible with newer versions of Windows. This feature was available as a free download for users of Windows 7 Professional, Enterprise, and Ultimate editions. It was not available for Windows 7 Starter, Windows 7 Home Premium, or Windows Vista Business. Windows XP mode helped businesses and individuals to run applications that were originally designed for Windows XP on their Windows 7 machines, delivering a virtual Windows XP environment.