Forgot the password to sign on. I did a reboot in safe mode to see if it would give me an option to reset password. It did not and I did the option for restart computer. The screen went black and I could still see the cursor arrow in middle of screen. I tried to force a shut down by holding the power button in. No matter how long I hold the power button, I see the brightness light ( set of three indicators on front left bottom: brightness, battery and wireless) flash 5 times, then nothing. ???? No idea what to do.