Windows driver for RTL283 device

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