This script works with HID class devices It transfer fixed size blocks of data over HID feature reports. You can use it with AVR V-USB example "hid-data" (http://www.obdev.at/products/vusb/download.html) Modified script #include <StructureConstants.au3> #Include <WinAPI.au3> Global Const $NULL = Chr(0) Global Const $DIGCF_DEFAULT = 0x00000001 ;// only valid with DIGCF_DEVICEINTERFACE Global Const $DIGCF_PRESENT = 0x00000002 Global Const $DIGCF_ALLCLASSES = 0x0000000