To Hide Drives ...

Open Registry Editor by going to run and typing regedit.Go to HKEY_LOCAL_MACHINE\software\microsoft\windows\currentversion\policies\explorerPut dword value="nodrive"To hide A drive hit enter and type 1.
Similarly for B drive put 2.
A:=1
B:=2
c:=4
d:=8
e:=16
To hide A and B(a:+b:)=1+2
67108863 to hide all

Try it on your own risk.