If you put your computer into hibernation, the next time you turn it on, you'll get all your windows and programs open just the way they were before the shutdown.
By default Windows calculator doesn't support order of operation, to enable the functionality you need to activate the scientific view, let me show you how.
Windows 7 have a nifty feature which combines the windows of opened applications under the same taskbar button. If you don't like it you can always turn it off.
Windows Explorer does not have menu displayed by default like you were used to in previous versions. To activate and keep it permanently visible follow this tutorial.
Neat little trick to force the preview images of running programs in Windows 7 taskbar or a so called Aero Peek, to show instantly with no delay at all.