Hard drive capacity discrepancy

The capacity of my 1 tet hard drive (wdbaazoo10hnc) is recognized as only 320 gigs in Windows Explorer but the full capacity is recognized in Disc Management.  How do I resolve this problem?

You can try doing a low level format, then reformat it.

How to low level format or write zeros (full erase) to a WD hard drive or Solid State drive

How to partition and format a WD drive on Windows (7, Vista, XP) and Mac OSX  

If this does not fix it you may confirm with your computer manufacturer if your system supports a 1 TB drive.  

Can you post a screenshot of your Disk Management screen? Dod you see any black line as unallocated space?