It appears that the system is affected by a 32-bit LBA limitation, in which case it could be a driver issue such as the following.
Intel Rapid Storage Technology (RST) drivers and Support for Disk Drives Beyond 2.2 TeraBytes (TB):
“Like other kinds of software, the Intel RST drivers are updated to keep pace with new technology. The Intel drivers found in retail releases of Windows 7 have a 2.2TB limitation. Rather than cut off the capacity at 2.2TB, the limitation expresses itself as the remainder above 2.2TB. In other words, the driver causes the Windows operating to see a 3TB drive as 746.52 GiB (or 800GB).”
BTW, I did search WD’s Knowledge Base for a similar explanation but I couldn’t find anything.