I have WinUSB installed as the driver for a USB device and everything seems to work fine the first time I access the device, I can read and write to the device. Once I close the device handles (bResult=WinUsb_Free(myDevInfo.winUsbHandle); and bResult=CloseHandle(myDevInfo.deviceHandle);), run my open routine, which worked the first time, I can not read from the device any more. bResult in both of the above statements returns TRUE, so the resources for WinUSB should have been released. Am I missing something, why can I not open the device, close the device and then open it again? I am writing the code in VC++ 6.0.