When I switched the theme to Windows default there was still no checkbox and autoplay still came up. With my 256MB usb just the folder pops up. That's ok. The 1GB pops up some U3 folder thing and the autoplay. Both of which the driver for the U3 and the driver for the 1GB usb I set to off in the properties. EDIT: The U3 driver has an autorun file, but I cannot delete it to see if it will stop the U3 from popping up.