Sony PCV-R553DS - Manual (Page 106)

VAIO Digital Studio™ Reference Manual 92
About User and Supervisor Passwords
The system allows you to specify up to two passwords (a User password
and a Supervisor password) in the CMOS Setup Utility. The User
password is required; the Supervisor password is optional.
Access to the CMOS Setup Utility depends on which passwords were
previously set, as indicated next.
If you set these passwords... ...the following passwords are required:
User password only User password is required at bootup.
Supervisor password only No password is required at bootup.
Supervisor password is required by most
setup options.
Both passwords User password is required at bootup.
Supervisor password is required by most
setup options.