Hi
1. I suggest you press and hold the power button of the PC until it powers off.
2. Disconnect all cables (including power cable from the PC. Please ensure that you check where those cables are connected so that while reconnecting them, it becomes easy for you.
3. Again press and hold the power button for 10 seconds and release it. It will discharge all static energy from the PC.
4. Connect all cables now and power on the PC. This should work and the PC should boot into Windows.
Please complete the steps below and let me know the outcome. Good luck!