Windows 3.0 is not a version of Windows available for the Windows Vista GUI. Any version of Windows before Windows 2000 are also not available.
So does Vista. There is the basic GUI and the Aero GUI. In order to run Aero, you need a compatible graphics card.
Vista has a Sidebar feature that allows you to see variously running apps on your desktop.
Windows Vista is the successor to Windows XP.
GUI based
windows indexing upgraded,and gadgets
Windows Vista Ultimate
EPS
Aero
No. It is simply a bug fix / minor feature addition to Windows XP. It does not contain all of the features or technologies of Windows Vista.
That feature is on some computers that have Windows Vista.
Windows Key + Tab
The main feature of Windows Vista Aero is the way Alt-Tab changed. Instead of small icons it now displays the available tabs in a 3D environment. Another associated feature is the windows popping up when hovering over the tabs in the taskbar.