Original sentence: It contains a number of new features, from a redesigned shell and user interface to significant technical changes, with a particular focus on security features.It has been subject to several criticisms.It is available in a number of different editions, more than any previous version of Windows
Edited sentence: This version of Windows contains hundreds of new re-designed features, including a new design of the "Start" menu and a new graphical user interface.Windows Vista is heavily criticized because it is very similar to Mac OS X and it consumes too much RAM and CPU usage