When/why did you do a recovery on the computer? When you open My Computer, what drives do you see? Don't just list the drive letters, what types of drives are they? Is D a second partition on your hard-drive? What size is drive D if you check it's properties? When you double-click on, you don't see anything in it? What if you turn on Show Hidden and Show System files, anything show up there?
IS this a prebuilt system ?? Most prebuilt systems will have a recovery partition installed by the manufacturer that has a copy of the HDD in its original shipped condition for use as a restore partition in case your HDD gets messed up for some reason you can then use that hidden partition to restore the system to its factory shipped state -- It is normally a hidden partition so that it is not accessible unless you set the system into restore mode so will show as empty in explorer since the actual files are flagged as hidden.
This next topics has been merged by Mousemonkey D Drive