The 8200 Elite stores administrator and power-on passwords inside the BIOS chip. Removing the CMOS battery will not clear these. The only reliable way is to dump the BIN file, modify the hex code to remove the password, and flash it back.
Alternatively, use a tool like 7-Zip to right-click and "Extract" the .exe directly. hp compaq 8200 elite bios bin file
: Updating to version 02.29 or 02.33 while using a non-EFI Windows installation can cause the system to hang for over 2 minutes during every warm reboot. Flashing Methods The 8200 Elite stores administrator and power-on passwords