Instruction on link included in the zip file or have a look to https://github.com/pbatard/libwdi/wiki/Zadig

Anyhow:
1. connect USBAsp device
2. wait unit windows will NOT install any driver
3. run zadig-2.3.exe (as Administrator!)
4. Your device USBAsp will appear into the app
5. To use with Companion 2.2 selet "libusb-win32 (v1.2.6.0)" in the middle of the app
6. enjoy