Here's what Toshiba suggests when all else fails
"If not already, ensure the computer is completely shut down. How To: Shut Down a Laptop with Windows 8
Now restart the computer by pressing the power button - IMMEDIATELY start tapping the F12 key on the keyboard until the "Boot Menu" screen appears.
Using the arrow keys, select <HDD Recovery> and press "Enter".
On the next screen you are asked to confirm if you want to contiue with recovery. Select "Yes".
The computer will bring you to the Advanced startup screen.
Select Troubleshoot.
Select Advanced options.
Select Startup settings.
Press Restart.
Select Safe Mode from the list."
found here under "Option 3"...