Hi guys, some real progress to report on this topic:
The start time got worse and worse and by chance I had the task manager open at one instance and noticed the following: As soon as I started Audacity the “Diensthost:Lokaler Dienst (Netzwerkeinschränkung)” subline: Windows-Audio popped up and used a very high CPU load. Sorry, for quoting the German text, it should translate to something like: Servicehost: Local Service (Netwerk restrictions) // Windows Audio. The load was very high until Audacity finally opened 30 seconds later.
I have then gone to the Device Manager and opened the Audio Devices Tab (making sure that also “Show inactive Devices” was ticked). I have then radically de-installed every single Audio Device, which was shown there. There were some dubious Microsoft devices visible, which I had no idea what they were good for.
I have then de-installed Audacity and finally restarted the computer. After the computer came up, I have gone back to the Device Manager und checked the found Audio Devices. All the dubious Microsft ones were still gone.
Re-installed and started Audacity and yes: Up and running in a second or so.
Happy.
Cheers Alfred