As one of the many security measures, to be able to hide and/or restrict access the local drives from your users can be an important matter. There are two ways of achieving this.

   1- Hiding drives with the admin tool :

Open an Admin Tool, and click on the "Security" tile.
Then click on "Hide Disk Drives" :


On the example below, I clicked "select all", which will check all the box corresponding to drives that will be hidden to everybody. 
A reboot might be necessary for changes to apply.

Yes, the hard drive will be hidden for everybody, this can be troublesome for administrators that have to work on the server for maintenance, update and so on.
To be able to see the drive from a remote session, open an explorer, as you can see below no drives are visible. Position your mouse on the target field.

Type in the location of desired folder :

   2- Hiding/Restricting access to selected drives to non administrator users :

The second option will allow you to be able to hide the drives and/or restrict access to drives to non administrators users, to achieve this you will need to follow the instructions of this FAQ first :

Once you have opened the Group Policy editor using the FAQ above, locate and open the following GPO :

User Configuration\Administrative Templates\Windows Components\Windows Explorer\Hide these specified drives in My Computer

By enabling this GPO, you will be able to select which drive will be hidden to your users. Hiding drives will still make them available for applications to be used. They also will still be accessible by opening a Windows Explorer and typing the address of desired folder.

If hiding drives is not enough you can also choose to prevent access to selected drives. Be aware that enabling the GPO below can lead to applications not to work properly because of access restrictions that might lead to this kind of error :

Locate and open the following GPO :

User Configuration\Administrative Templates\Windows Components\Windows Explorer\Prevent access to drives from My Computer

By enabling this GPO, you prevent your users from accessing the selected drives in any way possible. Applications may not work anymore so I recommend to test this one first to if it fulfill your needs.

GPO once applied should be operative immediately, if not you can force them by opening a ms dos box with the command : gpudate /force
To do so click start, execute and type in "cmd.exe"