Could you tell us how is your hard drive partitioned? Is Local disk D your only partition? If it is not, check if the other partitions are accessible. Run the Command Prompt as an Administrator and type the command:
Chkdsk D: /r
Wait for the process to finish and try to access the drive again. If the issue persists, I would recommend you to test the hard drive on another PC as a secondary storage drive. Try to access the drive and backup all important data. If that is not possible try using some data recovery tools. Check the link below for some suggestions:
If the data on the drive is really important, skip all instructions and call a Data Recovery Company. If the drive is damaged, any attempt to recover it may cause more trouble.
Hope this helps