Is this a new hard drive? Is the reason you cant access it because it doesn't show up? Or do you get some sort of error when you try to access it?
If you can take a look in Disk Management and see how it shows in there please.
Open the start menu and right click on Computer then press Manage. On the left hand side there is a menu tree. Under Storage you will see Disk Management, click on it. This should show all currently connected storage devices and how they are formatted etc.
Thank you for your reply. When I disconnect an external WD Passport or when I turn on the computer while WD is nt connected, , a window appleares with an X and says tuocaaf.exe-No Disk There is no disk in the drive. Please insert a disk into drive ..