This might be confusion over what "tablet mode" means. I think he just means the non-Desktop interfaces, which in Windows 8 you could unintentionally get into very easily, famously by double-clicking an image file. And back then, going back to the desktop was a lot harder - this was before they made the taskbar and window frame appear when you moved the mouse to the edge of the screen; you had to use arcane gestures or press the Windows Logo Key and click "Desktop".