Less Capacity Shown On Mapped Drive


I just set up a 4 TB My Cloud. On the Dashboard, it shows that there are 3.9 TB available. However, when I map the hard drive to windows, only 3.50 TB are available out of 3.57 TB, meaning that not only does it not show the full 3.9 TB available, but there is another 70 GB being used for something else. I have not copied any files on to this drive. Anyone have an idea of what could be causing this?

Thank you.

Windows reports drive space in Tebibytes (Base 2). WD reports in Terabytes (Base 10).

What could be “the” reason to have two units for the same thing? I do not understand this from the IEC, the IEC should create standards not double standards?

Sorry for my lack of …