IIRC that one is there because installing in a location where you don’t have write access (like Program Files) would cause errors. That one should be pretty evident as soon as you install.
The driver situation is a bit complicated. If you have the latest firmware update (0.21 on CWLite/Nano) and you don’t have any drivers installed for ChipWhisperer, it should automatically run with the correct drivers. The old drivers should work, but I’m currently investigating if that’s always true (works on my machine, but maybe not on others )
Now that you mention drivers, we did add a libusb dll since they wouldn’t be copied over to system32 when you installed drivers as in the past. That might be causing it. What’s your system configuration? Are you running 64-bit windows?