If you have a remote control for your X7 with an Air Mouse function (wave you remote control in the air, the cursor on screen moves), drop the cursor to the very bottom of the screen. HOLD DOWN the OK/select button, and flick the cursor (your wrist, effectively) upwards. This will restore the system/Android bar. If you don't have that type of remote control, plug in a USB mouse or similar, and repeat the procedure.