@shnki 

Hi,

Unless the event that says "requires further installation" is the newest of all logged events it should not indicate a problem, but is merely an information that at some point Windows waited for the driver to be installed. Check if there are other events like "Device configured" and "Device started" after the one that says "requires further installation". If you are unsure, then click on the button "View All Events" to see all the events in cronological order inside the Event Viewer.

Is Bluetooth not connecting in both directions? I mean, not just try to add a BT device from within Windows, but try to add the Windows computer from another device, like phone, tablet or another PC.

Was there ever another Bluetooth adapter/card installed on this computer? If yes, then show hidden devices in the Device Manager and see if there are any old (now hidden) entries for the Bluetooth device(s) that fail to connect now (e.g. your BT headphones or whatever device it is). In case there is/are, then delete that entry/those entries and see if that makes any difference.

  @woozle thank you so much for your answer!

Yes, I had another bluetooth device (a tplink usb stick) installed before.

I did what you recommended and removed the hidden bluetooth entries in the device manager.

Unfortunately this did not help, the bluetooth still won't find new devices and/or connect them in windows.

I could however as you suggested find my PC on my phone via bluetooth and pair it, but it won't keep connected.

Also I updated all kinds of drivers today even flashed the newest bios update.

Last thing I tried:

I disconnected my (working) usb-port and connected the cable to this usb.

Bluetooth shows on, but still connecting devices is impossible.

I begin to suspect there is something wrong with the usb from the tx20e.

I give up and return the tx20e.

  @shnki 

If you can't get the TX20E to work, then returning it would be the only option left.

Just one more thing. Do you have any external USB 3.x devices connected to your computer, like an external hard disk or SSD or whatever else nowadays uses USB 3.0?

USB 3.0 cables that are not of the highest quality (less than perfect shielding) are known to cause interference that can affect wireless devices that work at frequencies in the 2.4 GHz range, like Bluetooth.

So, maybe disconnect all cables and plug-in devices that are not essential from the computer and then check one more time if Bluetooth still can't establish a connection.

  @woozle thank you so much for your really great tips and help and effort!

No, I don't have an external hardrive or anything connected via cable.

Yes, unfortunately, I don't see anything else I could do...

Ensure that there are no other electronic devices or wireless signals causing interference with Bluetooth signals. Other wireless devices, USB 3.0 ports, and even some microwave ovens can interfere with Bluetooth connections.