To change the icons used for specific drives .
Open regedit by typing regedit into start->run

then navigate to

HKEY_LOCAL_MACHINE/SOFTWARE/Microsoft/Windows/CurrentVersion/Explorer

now create a key(KEY not VALUE!!) called DriveIcons under Explorer...
now within DriveIcons, create another key with the drive letter you want to change (e.g.,HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\DriveIcons\K)...
create another key within the drive letter key called DefaultIcon...
now set the default String value equal to the icon you want to use. if you have a file that has more than one icon in it, such as a DLL file, use the standard
C:\full_path\icon_file.dll,n ) where n is the number of the icon within the file icon_file.dll...