Some progress. This was not a permissions problem. It was because the SD card needed to be formatted by the special SD format utility. There were 2 partitions on the card. It needed to be cleaned out completely. Seems like this is a common-ish problem with Win32 Disk Imager, it took me a long time to identify the problem. The solution was here https://www.raspberrypi.org/forums/viewtopic.php?t=4949
I suggest that in your guide you add something like „If you get „Error 5 Access is denied“, then format the drive with the SD Format utility.“ That would have saved me about 3 hours of effort and frustration.
Having created the image on the SD card I booted the Pi and the GUI came up no problem. I activated it, set up my sound card and the power button add-on.
Then the damn thing rebooted and has been inaccessible ever since. I did not expand file system or update m2p. Now I cannot access the GUI.It is up and running, connected to my router, but I cannot access it. http://max2play just takes me to max2play.com after a pause.
NO GUI !! What did I do wrong? What do I do next?