Sometimes you may want to hide a drive from appearing in Computer or My Computer and on open/save dialogs, but still allow access to it from applications. For example, if you have a backup or network drive that you want applications to use but don’t want people to mess with, or a USB drive that’s solely used for ReadyBoost.
This takes a simple Registry change, but you must calculate the key value based upon the drive(s) you want to hide.
First, come up with a binary number. Visualize the alphabet in reverse order and put a zero below those drive letters you want to appear and a 1 for those you want to hide.
For example, if you wanted to hide drives A and F:
Z Y X W V U T S R Q P O N M L K J I H G F E D C B A 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1
Now convert that binary number (100001 for our example) to decimal form (33 for our example).
Now you can create the following Registry key and enter the calculated decimal number for the value:
DWORD Name: NoDrives