OK, rebooting didn't help.
But I hope you aren't angry I bothered you in vain, but I had my installation running sandboxed, and up until now, I never had problems with that (including low level things, driver installation, starting processes, etc.) ... so I was convinced, that wouldn't be the problem. But for the first time, it did turn out to be the culprit ...
thanks for helping anyways ...
there were three network adapters found now, so I guess your program will work