Below you can find the list of keyboard’s shortcuts that can be used in Windows Phone 8 emulator:

– F12 (first press) – turns off and locks the display,
– F12 (second press) – shows lock screen,
– Page Down – enables to use keyboard connected to PC in emulator,
– Page Up – disables to use keyboard connected to PC in emulator,
– F1 – simulates pressing Back button,
– F2 – simulates pressing Start button,
– F3 – simulates pressing Search button.

Check it:

Default ThumbnailWindows Phone 7 – Emulator shortcuts Default ThumbnailHardware keyboard emulation in Windows Phone 7 T9 Keyboard 1.0