W10 says that it cannot give me the startup menus or Cortana, what should I do?

[WPCentral Question]

W10 says that it cannot give me the startup menus or Cortana, and that,

Windows 10 worked well for some days. But today it didn't! I've been 'returning' all day with the same result. I cannot use any of the Office functions as the message sits in the middle of the screen, and even if I could I cannot send anything to anyone anyway!!!!