Detailed instructions are on page 63 of the user guide.

"To recover your hard disk drive using the utilities stored on your
computer’s HDD:

1 Make sure the computer is turned off.

2 Press and hold the 0 (zero) key on your keyboard while
powering on the computer. When the computer powers on, the
Toshiba Recovery Wizard screen displays."

Da: http://laptopforums.toshiba.com/t5/S...A79E498C5A517B