Did one of your drives drop out? I usually get an ATAPI error when one of my sata drives drops out. Usually doing a "scan for new hardware" in the device manager brings it back. Not sure why it shows up for hard drives though as ATAPI is usually referencing CD/DVD drives and tape backups.
ATAPI (AT Attachment Packet Interface) is an interface between your computer and attached CD-ROM drives and tape backup drives. Most of today's PC computers use the standard Integrated Drive Electronics (IDE) interface to address hard disk drives. ATAPI provides the additional commands needed for controlling a CD-ROM player or tape backup so that your computer can use the IDE interface and controllers to control these relatively newer device types.
ATAPI is part of the Enhanced IDE (EIDE) interface (also known as ATA-2).