Intel Precision M2400 Administrator's Manual page 62

One lowercase letter
A number
A special (nonalphanumeric) character, such as !, $, or ; excluding the :, ", and , characters.)
The underscore ( _ ) and spacebar are valid password characters but do NOT add to the password complexity.
4. Change the password to establish Intel AMT ownership. The computer then goes from the factory-default state to the
setup state.
5. Select Intel ME Configuration, and then press <Enter>.
ME Platform Configuration allows you to configure ME features such as power options, firmware update capabilities,
and so on.