I have now used 7-Zip (all ok but haven't checked yet) but after uninstalling and reinstalling ATK, still it's telling me no USB detected. During install I did nothing differently but this time it asked me to confirm I wanted half a dozen drivers installed, had to say yes to each, which gave me hope that the drivers were installing... but no.
Also during install, a DOS-look window came up (years since I've seen that) and told me I had to have administrator privileges to install these drivers, which surely is irrelevant as (a) I'm the only user and have full privileges (always sounds so posh, like the members' enclosure), and (b) ATK did install. ??
Or should the kindle be connected before running ATK? In the debrick guide, plugging it comes next, not before.