How to get the Start Screen back in Windows 10 (TP 9860)
This trick will allow you to restore the Start Screen on Windows 10. It should be noted that this trick works Technical Preview version of Windows 10 (Build 9860) and that the interface may change for the final version.
Windows 10 Technical Preview.
About Windows 10
Windows 10 fully integrates the "Start Screen" of Windows 8, in the Start Menu. It is no longer necessary to switch between the desktop and Start Screen to launch apps downloaded from the Windows Store. Apps run directly on the desktop, through a classic window (with the maximize, minimize, close..buttons).
Restore the Start Screen
Right click on the taskbar> "Properties".
Once the "Taskbar and Start Menu Properties" window is open click on the "Start Menu" tab.
Now uncheck the "Use the Start menu instead of the Start screen".
Windows will prompt you to restart your session, so click "Sign out and change settings".
Connect to your session, the Start screen is back!