Al Robertson wrote: > I looked at the .CAT files for 1.6.0 and found that they contained the > following text. Perhaps that is causing a problem. If so, a simple > zero-byte .CAT file might be another way to make this work. Right, that's directly from libusb-win32. > Also, I tried installing the 1.6.0 ColorMunki (Argyll) driver on Win8.1 > 64-bit, build 9471 using Argyll's instructions for disabling digital > signature checking on Win8. This isn't quite the final version of the OS, > but it is recent. > Surprisingly, the unmodified driver installed fine. I don't know what > accounts for the difference. It's a little tricky since the same .inf and driver install is used for all the instruments, so once one device is installed, others can just be just plugged in. The flip side of this seems to be that if you remove the drivers for one device, it actually leaves the libusb0.sys installed (so the "other" devices don't stop working), so a re-install of the device doesn't actually install libusb0.sys and may not go though the same checks. I've tried manually deleting the libusb0.sys as a way of getting closer to a fresh system for testing. An interesting discovery is that it seems that with valid (if unsigned) .cat files + the signed libusb0.sys, there is no need to disable diver signature enforcement, you just have to acknowledge the security popup ! (ie. it returns to the Win7 behaviour.) So the need for that may simply been a symptom of having invalid .cat files and Win8 being more picky about it. If so, this will allow a simpler install procedure with the next release. Graeme Gill.