content: It's the Power User Menu, you can also get it from Win+X. (Confirmed by /u/KyJoCaThe2nd). Vastly more useful than the "Windows Mobility Center" that Win+X brought up in Windows 7.  Administrative command prompt with Win+X then "A" was really useful. It's one of the things I miss after downgrading back to 7 on my laptop. Another was the superior Task Manager.