Boot camp repair installation freezes at enumerating pre-install packages after update to Windows 10

I'm on a mid 2015 15" MBP, and my right click and function keys have stopped working after updating to Windows 10, so I'm trying to repair the boot camp driver installation. I'm using drivers downloaded a couple of days ago using BCA onto a USB drive, but it freezes every time at "Status: Enumerating pre-install packages".

I thought maybe a clean install would help, so I removed every part of Boot Camp I could find. So now it still sticks at the same stage, only now my wi-fi doesn't work either.