My 2TB Caviar Black WD2002FAEX is doing the exact same thing as this user posted in April. DLG Diag for Windows V1.24 extended test says it passed, but when I format a 1725 GB NTFS partition on Windows 2003 SP2 it reports almost 900 GB in bad sectors. Was there a resolution to this problem? Am I doing something wrong? Thanks, Dan.
If DLG detects the full capacity of the drive, then you may have a driver problem. Some NVIDIA nForce drivers, for example, had a 1 TiB limitation which was fixed by a driver update.
Otherwise, if DLG reports a capacity of 1TB, then see the following thread for an explanation and solution:
http://forum.hddguru.com/lost-partition-hitachi-1gb-hdt721010sla360-t15662.html
I’m currently compiling a HDD Capacity FAQ, so I would be very interested in your outcome.