Why does my ThinkPad T61 have a black screen with a hard drive and a padlock icons?

[Windows Central Question]

ThinkPad T61 has a black screen with a hard drive and a padlock icons

Will not boot because forgot password. Rescue and recovery boot disks for windows xp does not work. Removing the cmo battery does not work. Hard reset does nothing. Hardware OK (diagnostic. Motherboard should be replaced?

 

[Laura Knotek]

It has a hard drive password set.
A hard drive password protects hard drive data from unauthorized users. Once a hard drive password is set, data on the hard drive cannot be accessed without the correct hard drive password. Because this password is stored in the hard drive, the data remains protected even if the hard drive is removed to another system. The hard drive password prompt appears:
•Each time the system is turned on.
Detailed specifications - ThinkPad T61, T61p - Lenovo Support (US)