Is it working? OK. If not, then continue with this guide.

Once installed, you should set its .exe, which can be found here C:\Program Files (x86)\2N TELEKOMUNIKACE\2N Helios IP\2N Helios IP USB Driver\Usbdrv.exe, to always run as administrator:

Your hosts file, which you can also find here: C:\Windows\System32\drivers\etc\hosts, should get updated during the installation. Check if it contains this line:
127.0.0.1       localhost.2n.cz
If it doesn’t, you’ll get this error in Chrome Console (F12) while trying to detect the driver:

Then either add it manually or recheck that you really disabled everything mentioned, then reinstall and check again.

„Server can not be started! Make sure that port 8181 is available, then restart 2N Helios IP USB Driver“ error message

This error can come up when you’re trying to launch the app and something else is using port 8181. But I’ve also seen it when the app was running on a limited-privileges account. So, I ran it as admin and everything was ok. Every time the app is started, it should occupy this websocket port. Once you turn it off, it should become vacant again.

You can run this cmd command to check if something is using port 8181:
netstat -an

If you see 0.0.0.0:8181 while the app isn’t running, then there’s another app that uses this port.

Websocket connection test from within a browser

Also related to the port is this websocket test webpage. It can test whether port 8181 is accessible from the browser or not.

Once you click „Connect“ you should get a „CONNECTED“ response and not an error in the log.

Websocket connection test without browser

You can use websocat_win64.exe tool to check websocket communication without a browser.

Save it to a computer where the driver is installed, run command line, navigate to the folder containing the .exe, and run the following command:

websocat_win64.exe -v wss://localhost.2n.cz:8181

If there's an error message shown, it means it's not a browser issue and there's something blocking the communication, otherwise the tool will be connected to websocket and awaiting commands; you can stop it using Ctrl+C.

Proxy in effect?

The USB driver installer doesn’t add localhost.2n.cz into the windows proxy whitelist because it’s not necessary by default. Therefore, in order to get it working in a proxy scenario, you have to add it manually into exceptions here:

Still not working?

What’s happening?
Can you replicate it after reboot?
Windows version/build?
Is .NET installed in Windows functions?
Get screenshots.
Try to save Console logs if possible.