One of the complaints with Windows 8 was that when the computer boots up/starts up it goes to the new Windows Start screen instead of the traditional Windows desktop. The new start screen is a bit of a complicated area for someone who is not IT Savvy or new to computers.
There were many 3rd part utilities which were made available to tweak Windows (modify some registry keys) in order to make Windows 8 boot directly to the desktop.
With Windows 8.1 Microsoft took the valuable feedbacks from its customers and reintroduced the start button as well as gave the option to boot directly to Windows desktop instead of the new start screen. To do this,
1) Right Click the taskbar and select properties
2) The properties Window, click Navigation
3) Select the highlighted option (checkbox) and click OK. you are done