Compatibility
Windows Vista faces backward compatibility problems with many of the games and utility programs that work in Windows XP. As of July 2007, there were about 2,000 applications that specifically carried the 'Vista Compatibility Logo', although the majority of applications without the logo will run without any problems. This number is low compared to the number of programs that can currently work under XP, either natively or in simulation modality.
Read more about this topic: Comparison Of Windows Vista And Windows XP