1: GO TO run then type in regedit.exe and open it.
2:search or scroll down the following registry key:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
(for system wide restriction)
or
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
(for user specific restriction)
3:create a new DWORD value, "NoViewOnDrive" and set its data value to the number of the drive that you want to    hide as per the bilow list:
A:1, B:2, C:4, D:8, E:16, F:32, G:64, H:128, I:256, J:512, K:1028, L:2048, M:4096 AND SO ON.
4:Exit the windows registry and restart the windows session for the changes to come into effect.