In short, Windows is recognizing the hard drive properly and there's nothing to worry about. The confusion lies in the terminology when measuring the volume of a hard drive...see gigabyte (GB) vs gibibyte (GiB).
Hope this helps,
I have a 400GB Seagate SATA hard drive.
The entire C:\ drive is formatted.
Disk Management shows capacity is only 372.60GB's.
That's not a good thing, is it......?