Found this in HP 2133 Service Repair Manual:

Unknown user password
If the computer you are servicing has an unknown user password, follow these steps to clear the
password:
NOTE: These steps also clear CMOS.
1. Shut down the computer. If you are unsure whether the computer is off or in Hibernation, turn the
computer on, and then shut it down through the operating system.
2. Disconnect all external devices connected to the computer.
3. Disconnect the power from the computer by first unplugging the power cord from the AC outlet and
then unplugging the AC adapter from the computer.
4. Remove the battery (see Battery on page 44).
5. Remove the real-time clock (RTC) battery (see RTC battery on page 66).
6. Wait approximately 5 minutes.
7. Replace the RTC battery and reassemble the computer.
8. Connect AC power to the computer. Do not reinsert any batteries at this time.
9. Turn on the computer.
All passwords and all CMOS settings have been cleared.
Preliminary

Thanks HP! lol