The USBASP windows driver is based on libusb-win32. A while back they released version 1.2.6 and this has now been packaged up for the USBASP. The download link is below: https://protostack.com.au/download/USBasp-win-driver-x86-x64-ia64-v1.2.6.zip This driver should work with version of Windows, XP and higher (both 32 and 64 bit editions).