Q: iPad Air & Win 10: Error 28, Driver not available

I can't get my iPad to be recognized as a device by a PC running Windows 10. The connection with iTunes works fine but the iPad doesn't show up as a device in the explorer.

In the device manager the iPad shows up as "iPad" in the category "other devices". The device status is "The drivers for this device are not installed. (Code 28)".

Here's what I tried:

• I updated iTunes and the iPad to current versions.
• I deinstalled and reinstalled iTunes.
• I tried to update / install the proper driver manually with the information given here: If iTunes doesn't recognize your iPhone, iPad, or iPod - Apple Support. After the update the iPad then shows up in the category "USB controller" as "Apple Mobile Device USB Driver". But after a few seconds another "iPad" is found in "other devices". Manually installing the driver for this second "iPad" entry leads to the same results. I repeated this a few times and it just adds more entries of "Apple Mobile Device USB Driver".

What am I missing?