From Maintenance & Service Guide (page 236) of the 3rd link I sent earlier:
Resetting the Password Jumper
To disable the power-on or setup password featur
es, or to clear the power-on or setup passwords,
complete the following steps:
1.
Shut down the operating system pr
operly, then turn off the comp
uter and any external devices,
and disconnect the power cord from the power outlet.
2.
With the power cord disconnected, press the power
button again to drain the system of any residual
power.
WARNING!
To reduce the risk of personal injury fr
om electrical shock and/or hot surfaces, be
sure to disconnect the power cord
from the wall outlet, and allo
w the internal system components
to cool before touching.
CAUTION:
When the computer is plugged in, the power supply always has voltage applied to
the system board even when the unit is turned off. Failure to disconnect the power cord can result
in damage to the system.
Static electricity can damage the electronic co
mponents of the computer or optional equipment.
Before beginning these procedures, ensure that yo
u are discharged of static
electricity by briefly
touching a grounded metal object. See the
Safety & Regulato
ry Information
guide for more
information.
3.
Remove the computer cover or access panel.
4.
Locate the header and jumper.
NOTE:
The password jumper is green so that it can
be easily identified.
For assistance locating
the password jumper and other system board comp
onents, see the Illustrated Parts & Service Map
(IPSM) for that particular system. The IPSM can be downloaded from
http://www.hp.com/
support
.
5.
Remove the jumper from pins 1 and 2. Place the jumper on either pin 1 or 2, but not both, so that
it does not get lost.
6.
Replace the computer cover or access panel.
7.
Reconnect the external equipment.
8.
Plug in the computer and turn on power. Allow th
e operating system to start. This clears the current
passwords and disables the password features.
9.
To establish new passwords, repeat steps 1 throu
gh 4, replace the password jumper on pins 1 and
2, then repeat steps 6 through 8. Establish the
new passwords in Computer Setup. Refer to the
Computer Setup (F10) Utility Guide
for Computer Setup instructions