First of all, you posted a question about OpenSprinkler in the SquareWear thread, that’s kind of confusing to me. Next, as I said, you need to install USBtiny driver, not USBasp! The readme I was talking about is the Firmware Updater software. Specifically, at this link:
http://rayshobby.net/?page_id=732#upload
download and unzip the Firmware Updater program for your operating system (in your case, windows 64-bit). Next, in the unzipped folder there is an applications subfolder with a .exe file you can click and it will run. There is a big ‘README FIRST’ button at the top. That’s the readme I was referring to. The instructions are brief but contain only the necessary information so you don’t have to read a lot. Please first let me know if you have run the Firmware Updater program, then we can continue from there. Also, I am going to move this to the OpenSprinkler thread since it has nothing to do with SquareWear.