With the toshiba correctly shutdown and off. Tap F12 on the top rows of keys on keyboard and then turn the unit and it will give you a selection of Options to boot From.
Turn the Unit off and turn the unit on whilst tapping 0 on the top number keys and this will luanch HDD Recovery. If Windows 8 Select troubleshooting and then reset your system dont use the Toshiba Maintance software in windows 8.