Try disabling Autorun feature for drives

1.START ->RUN ->Key in 'regedit' to open registry.

2. HKEY_CURRENT_USER\ Software\Microsoft\ Windows\CurrentVersion \Explorer\MountPoints2,

3.Right click 'mountpoints2' and select 'permission'

4.Then click 'Advance',uncheck 'inherit from parent the permission entires that apply to child objects.Include these with entires explicity defined here'.

5.Click 'remove'.'Yes' and 'ok'.