@David57: I wonder if you could try something for me...
Open a windows command prompt and type
diskpart
There will probably be a prompt from Windows to allow a program to make changes to your computer. Select the OK button
Then type
automount
This will display the setting for automatically mounting drives on your computer.
Cut and paste the output in a reply here, or if needs be take a screen print if that's easier.
Finally type
exit to leave diskpart.
Thanks
Peter