USBasp driver- where should it show in Dev Mgr?

Do this:

  • Download Zadig: http://zadig.akeo.ie/. Note that Zadig is recommended on the official USBasp page: USBasp - USB programmer for Atmel AVR controllers - fischl.de.
  • Plug in your USBasp
  • Start Zadig
  • From the dropdown menu, select USBasp. If it doesn't show up on the menu, then select Options > List all devices and check again.
  • Click the up or down arrows next to the Driver selection box on the right side until you see libusbK.
  • Click the "Replace Driver" button.
  • After it finishes you can close Zadig.

That should solve your problem with USBasp. I have no experience with Tinyasp but you can try the same. Zadig allows you to install libusb-win32 again if you like.