hi tankapotamus
you dont need xFSTK under windows
i would recommend the following way
1) download and extract edison-image-rel1-maint-rel1-ww42-14.zip to your hd
2) download dfu https://dl.dropboxusercontent.com/u/54378433/dfu-util/dfu-util.exe and save it in the same folder
3) edit the flashall.bat and add -R to the following line
echo Flashing U-Boot Environment Backup
call:flash-command --alt u-boot-env1 -D %VARIANT_FILE% -R
4) run flashall.bat (should now wait for edison)
5) power up edison and press a key to stop autoboot (Hit any key to stop autoboot: 1)
6) run do_flash (boot > run do_flash) and press enter
br
Andre