Window problem
Your device is, most probably, in bootloader mode, state in which it is starting to be fllashed with a new ROM. A simple press on the reset pin, with the stylus pen, should suffice to turn it back to life. Othewise, I'm afraid you'll have to hard reset your device. You, most probably, know that a hard reset will delete all the applications you have installed, as well as your personal data and settings. Hope you have a recent backup, to be used afterwards. Anyway, to hard reset your device, open its screen to reveal the hardware keyboard. Then, press and hold both softkeys on the keyboard (the ones marked with '-'), and, whilst keeping them pressed, briefly press the reset pin with the stylus pen. Release the softkeys when a screen asking for confirmations comes up. Confirm the procedure by pressing 0 (zero).
Hope you are able to sort your problems out.
Regards,
Carlos