You can create a Parted Magic OS boot on a USB stick. Boot and under System Utilities choose secure erase - it will alert you to the security freeze and request you enter sleep state to remove it, do this and youre unfrozen.
Just trying this myself it says it still is frozen. Parted Magic 12_30
Still the drive says it's frozen when booting back up to Windows 7 and it says it's write protected.