By default USB drives have auto run disabled, there is a registry keys that effect this, it is located for the entire machine
or the currently logged on user
The machine setting overrides the the user setting if both are set (on my XP box it was only listed under the user setting).
The value of this key is a bitmask, you need to add the values together to get the combination you want.
- 0x1 Disables AutoPlay on drives of unknown type.
- 0x4 Disables AutoPlay on removable drives.
- 0x8 Disables AutoPlay on fixed drives.
- 0x10 Disables AutoPlay on network drives.
- 0x20 Disables AutoPlay on CD-ROM drives.
- 0x40 Disables AutoPlay on RAM drives.
- 0x80 Disables AutoPlay on drives of unknown type.
- 0xFF Disables AutoPlay on all types of drives.
So if you want to enable USB drives you will need to "subtract" 0x4 from the value you have (but only if the number has the 4 bit set).
This solution works all the way from Windows 7 to XP and likely works on windows 8 but is untested by me.
Read more: http://www.fortypoundhead.com/showcontent.asp?artid=2705