According to Microsoft, Windows Vista contains hundreds of new features; some of the most significant include an updated graphical user interface and visual style dubbed Windows Aero, improved searching features, new multimedia creation tools such as Windows DVD Maker, and completely redesigned networking, audio, print, and display sub-systems. Vista also aims to increase the level of communication between machines on a home network using peer-to-peer technology, making it easier to share files and digital media between computers and devices. For developers, Vista introduces version 3.0 of the .NET Framework, which aims to make it significantly easier for developers to write high-quality applications than with the traditional Windows API.

Microsoft's primary stated objective with Vista, however, has been to improve the state of security in the Windows operating system.One of the most common
criticisms of Windows XP and its predecessors has been their commonly exploited security vulnerabilities and overall susceptibility to malware, viruses and buffer overflows. In light of this, then Microsoft chairman Bill Gates announced in early
2002 a company-wide 'Trustworthy Computing initiative' which aims to incorporate security work into every aspect of software development at the company. Microsoft claimed that it prioritized improving the security of Windows XP and Windows Server 2003 above finishing Windows Vista, significantly delaying its completion.