Help!!! Everything was working fine, until suddenly at youtube the videos were running unsmooth. I tried to restart, but when clicking restart / turn off, nothing happened. I put the notebook in sleep mode, using the power button. When hitting the power button again, it didn't go back to the windows logon screen. After the Samsung logo dissapeared, I had a black screen with only the mouse showing.

I tried several times again, same result. I can access the Secure Core Setup Menu pressing F2, but nothing else.

I have a Samsung Series 5 Notebook, Windows 8, only external CD drive (usb).

Please help.