HP Compaq Presario,Presario 800AP Supplementary Manual page 44

6. Press the Enter key on the Enter new Power-On password
line.
7. Press the Enter key on the password verification line.
8. When [ ] Enable password is highlighted, disable the
old password by pressing the Space Bar to remove the X
from the brackets.
9. Press the Enter key to return to the menu bar options.
10. Using your arrow keys, select the Exit option from the menu
bar and press the Enter key.
11. Select the Save Changes and Exit option and press the
Enter key.