Yesterday I've spent like 2 hours fighting to make USBasp ISP programmer work under Windows 10 64bit. Seriously, that was like some kind of nightmare that turned into a comedy. All web pages that I've found suggested following procedure:

  1. Download zadig
  2. Install libusb-win32
  3. Be happy

Unfortunately, in my case all attempts failed miserably. All I was getting from avrdude was

avrdude: error: programm enable: target doesn't answer. 1 
avrdude: initialization failed, rc=-1

I've found a solution. Internet was wrong. libusb-win32 was not the correct driver for USBasp. The correct driver was libusbK (v3.0.7.0). After installing libusbK USBasp came back to life!

usbasp driver for Windows 10 64bit