Is this something that just started? Were the partitions you show in the attachment the original ones?
Since it seems to be OK in safe mode, do you have any third party software that might effect access?
Your attachments do not really show what access you give to the users for the drive, but although I have not tested, I would think the security restrictions would be active in safe mode also.
Possibly, since this is an OEM install, the D: partition has taken on the properties of the Recovery partition which may have been inaccessible in the original configuration. Have you tested your Recovery options lately to see if they work?