Acer TravelMate P255-MP - Manual (Page 48)

48 - Acer ProShield
Click Start to begin. You will be required to set a password, and can
choose to create a Personal Secure Drive.
Once you have set a password, you can click Next to proceed to
setting up a Personal Secure Drive or click Finish to exit the wizard.
Note
Select a password that you will remember, but is difficult to guess. Do not use
words that can be found in a dictionary. It is advisable to use a combination
of letters and numbers.