How to hidden drives?
1- Run regedit,for this follow >>>Start\Run\Regedit
2-Go to following address:
[HKEY-CURRENT-USER\Software\Microsoft\Windows\Currentversion\Policies\explorer]

3-Create new key (Dword Value ) and name it "Nodrives".
4- Different drive have a separate value for example:
Drive A >> 1
Drive B >> 2
Drive C >> 4
Drive D >> 8
Drive E >> 16
Drive F >> 32
.
.
.
.
Drive number n >> 2^n

And finally you should restart your computer .