How to make hard-drive inaccessible?

When double clicked on this drive an error message will open saying it is inaccessible .This is an alternate to hiding a drive and making it inaccessible.
Here's how u do that :

Go to the registry editor and navigate to the following place :
HKEY_CURRENT_USER\Software\Microsoft\Windows\Curre ntVersion\Policies\Explorer
In the right hand pane for the Explorer key, create a new "DWORD" value named ViewNoDrive

Double click the new value and enter it as .......
for hiding A drive set value as 1 , for B its 2 and C its 4 and so on and for Z its 33554432
generally multiply it by 2 for the next alphabet to hide

Once done, reboot or log off and login in again. Then try double clicking the drive you made inaccessible.

You should receive a message stating that the drive cannot be accessed.