Xp200 power on password - Lenovo ThinkPad X200 Notebook

Power On password The Power on Password and hard drive password is used to protect the laptop/computer and hard disk from unauthorized access.
The hard drive password is setup in the BIOS you need the hard disk password to remove the password. I'm afraid you may have purchased a stolen laptop/computer. It is impossible to remove a hard drive's password there are no backdoor passwords because the password is stored in the hard drive's firmware. If the laptop/computer has a Power on Password then this laptop cannot boot up.
If the hard drive is password protected then remove the existing drive, replace it with a new hard drive may fix the laptop/computer r BUT it may also set a password on the new hard disk and lock it with the same password. If it does not password protect the new hard drive, then install Windows plus laptop/computer's device drivers and programs to get a working laptop/computer.