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
Windows Vista years earlier. Shortly after however, due to Vista's relatively low adoption rates and continued demand for Windows XP, Microsoft decided to sell Windows XP until June 30, 2008, instead of the previously planned date of January 31, 2008. There were reports of Vista users "downgrading" their operating systems, as well as reports of businesses planning to skip Vista. A study conducted by ChangeWave in March 2008 showed that the percentage of corporate users who were "very satisfied" with Vista was dramatically lower than other operating systems, with Vista at 8%, compared to the 40% who said they were "very satisfied"