The HDrive is capable to hold a HTML file with a size of 100 KB. This file is stored inside a dedicated section inside the Flash memory of the micro-controller.
To make the HDrive accepting an HTML file, it is mandatory, to rename the file to the ending “.htmlmin”. The intension there, is to use a minifier – but this is not important here because the file weight is only a couple of kilobytes.
Instruction:
First enter the “Fallback” Web GUI from your drive by navigating to http://192.168.1.102/fallback.html
This page is always available, also if the Web-gui would have been deleted.

Click on “Upload Web GUI” to upload your .htmlmin file. This should only take several seconds.
The HDrive is restarting automatically after a successful upload.
The upload process is finished as soon as the drive is ready again (green blinking) .