2006: Windows Vista
Windows Vista, released at end of 2006, may well be the most criticized and disliked version of Windows of all time. Released more than five years after Windows XP, Vista faced widespread hardware incompatibilities upon launch and wouldn't run on older hardware.
Vista's interface was significantly different from XP's interface. Most notably, it had a new feature called Windows Aero, a set of visual enhancements that included transparent windows and animations. There were also a variety of other new features, including the Windows Sidebar, Desktop Gadgets, the Windows Photo Gallery and improved search. Some people disliked Vista's resource-hungry user interface, and those who did like it couldn't always get it: Many PCs that were sold as "Vista-capable" couldn't run the full version of Vista, leading to a class-action lawsuit against Microsoft.
Windows Vista was available in six different versions. Most PCs were sold with Windows Vista Home Premium. It required a 1-GHz processor (either 32- or 64-bit), 1GB of system memory, 15GB of free hard disk space and a graphics card that was able to support Windows Aero.