Apparent factory lock on "Set User Password" in BIOS

I bought a used Studio 1558 to replace the one I had purchased from Dell back in 2010 (which was stolen in a break-in at my house) and I am now much more security conscious.  The laptop that was stolen had no password protection at all, so now I want to put a ton of security on the new laptop.

I want to add password protection through the BIOS (Phoenix is what I have), but the field for "Set User Password" displays "Locked" in grayed-out letters and it cannot be selected.  Also, lower in the option list, the option for "Password on Boot" says "Disabled" in grayed-out, unselectable text.

I totally wiped this new laptop and used my system restore disks from my original laptop, and it is running Windows 7 Home Premium, 64-bit with Service Pack 1.

Is this a factory-set fail-safe to keep users from adding a BIOS password?  More importantly, is there a way to unlock these options so that I can add the extra layer of password-based security that I want?

Thanks in advance for the help!