Asus RS120-E4/PA2 - Manual (Page 121)

ASUS RS120-E4/PA2 6-15
3. When prompted, use the arrow keys 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.