Asus TS300-PA4 - Manual (Page 147)

ASUS TS300-E3/PA4 & PS4 6-19
3. When prompted, press the <SpaceBar> to select Yes from the Initialize?
dialog box, then press <Enter>. You may also press <F10> to initialize the
drive without confirmation.
Initializing a logical drive(s) erases all data on the drive.
4. A progress bar appears on screen. If desired, press <Esc> to abort
initialization.