I did recently. Firmwares are here: http://deconz.dresden-elektronik.de/deconz-firmware/?C=M;O=D
And flasher is here: http://deconz.dresden-elektronik.de/win/
Use the command line as described here for Windows: https://github.com/dresden-elektronik/deconz-rest-plugin/wiki/Update-deCONZ-manually#update-in-windows