Windows 7 worked on Windows 7. These were broadly divided into "core operating system" and "Windows client experience", in turn organized into 25 teams of around 40 developers on average. In October 2008, it was announced that Windows 7 would also be the official name of the operating system. There has been some confusion over naming the product Windows 7, while versioning it as 6.1 to indicate its similar build to Vista and increase compatibility with applications that only check major version numbers, similar to Windows 2000 and Windows XP both having 5.x version numbers. The first external release to select Microsoft
Features new to Windows Vista for Windows Vista was developed with the SDL methodology, and all existing code was reviewed and refactored to improve security. Some of the most significant and most discussed security features included with Windows Vista include User Account Control, Kernel Patch Protection, BitLocker Drive Encryption, Mandatory Integrity Control, Digital Rights Management, TCP/IP stack security improvements, Address Space Layout Randomization and Encrypting File System and cryptography improvements. Additionally, Windows Vista includes a range of parental controls, which give owners of a computer a set of tools to limit what other accounts on a computer can do, and an improved Windows Firewall which