Compaq Armada 7400 Reference Manual page 84

Once you have enabled DriveLock protection and established user
master passwords, you can only change the password after the
computer has restarted and the protected hard drive has been
unlocked.
1. Turn on or restart the computer and enter your current user
password.
2. Run Computer Setup.
3. Select the System Features icon Æ Security Management box
Æ DriveLock tab.
4. In the Current Drive section, select either hard drive bay or
MultiBay.
5. In the Master Password section, select Change.
6. Type the old master password.
7. Enter your new master password. (You may use up to
32 alphanumeric characters, and you may use the same
password you are using for the power-on password.)
Type carefully because the password does not display
as you type it.
8. Enter the password again to verify it.
9. Select OK.
Security