AIUI, laptops write an ATA password to a hidden System Area on the drive. This area is inaccessible to the user. When the drive powers up, it does not permit read access to any data until such time as an ATA password challenge is satisfied. This means that the password challenge must come from BIOS, not via software. Therefore, unless your desktop has a BIOS that supports this feature, you need some other way to implement such a password.