It looks like this answers my question. The libusb documentation at http://www.libusb.org/wiki/windows_backend also points to Zadig as the way to control what driver is used. Thanks.

On Thu, Jan 17, 2013 at 3:12 PM, Moses moses.mason@gmail.com wrote:

I'm using Zadig (http://sourceforge.net/projects/libwdi/files/zadig/) to replace the driver comes with the device with the WinUSB driver, which is very easy to use and works fine for me. At the end of my replacing, it maybe pop a error message box indicates the replacing is failed, but in fact, after checking the hardware manager, the driver is installed correctly and works very well.

On Sat, Jan 12, 2013 at 12:03 PM, Robert Durkacz robert.durkacz@gmail.com wrote:

...

Hello,

I am using cygwin with Windows XP but I do not have a good understanding of the Windows OS. I could do with some advice about how the usb driver for the RTL2832U device is meant to be located by the rtl_sdr.c program using the libusb library.

For me this program fails with a libusb_open() error of -12. Using the debugger I can see this is due to no driver being found for the RTL2832U device.

When the function get_api_type() in windows_usb.c is called it consults the registry for a driver name for the device. In my case it finds RTL2832UUSB and RTL2832UBDA but I suppose this just depends on what is sitting in the registry. Subsequently the program checks to see if the driver name is WINUSB or USBCCGP. Because it is not the program cannot work.

Am I meant to ensure either WINUSB or USBGCCP drivers are installed on my computer and must the registry entry for the RTL2832U device point to one of these? If so, is there a recommended procedure to do that?

Thanks for any advice Robert Durkacz

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