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.
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.
If you leave your computer running on a 24/7 basis you might be interested in determining the amount of uptime that has accumulated since the last reboot.
You have more people using one computer and you don't want them to be able to shut it down using a shutdown button on Windows logon screen, this is how you remove it.