The key was/is to find out where in the registry Desktop location is stored.
Seems easy enough, huh.
Unfortunately, Windows wants that information in hex.
So, here are my four desktops, that I switch among. I created four reg files, to double click on, when I want to use any particular one of the desktops. (As said earlier, the actual folders of these desktops are side by side where everyone else's desktops are, c:\users\username\...):
Desktop#0 (original desktop, populated with tons of icons, way too many...)
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders]
"Desktop"=hex(2):43,00,3a,00,5c,00,55,00,73,00,65,00,72,00,73,00,5c,00,4e,00,\
69,00,63,00,68,00,6f,00,6c,00,61,00,73,00,5c,00,44,00,65,00,73,00,6b,00,74,\
00,6f,00,70,00,00,00
Desktop#1
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders]
"Desktop"=hex(2):43,00,3a,00,5c,00,55,00,73,00,65,00,72,00,73,00,5c,00,4e,00,\
69,00,63,00,68,00,6f,00,6c,00,61,00,73,00,5c,00,44,00,65,00,73,00,6b,00,74,\
00,6f,00,70,00,23,00,31,00,00,00
Desktop#2
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders]
"Desktop"=hex(2):43,00,3a,00,5c,00,55,00,73,00,65,00,72,00,73,00,5c,00,4e,00,\
69,00,63,00,68,00,6f,00,6c,00,61,00,73,00,5c,00,44,00,65,00,73,00,6b,00,74,\
00,6f,00,70,00,23,00,32,00,00,00
Desktop#3
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders]
"Desktop"=hex(2):43,00,3a,00,5c,00,55,00,73,00,65,00,72,00,73,00,5c,00,4e,00,\
69,00,63,00,68,00,6f,00,6c,00,61,00,73,00,5c,00,44,00,65,00,73,00,6b,00,74,\
00,6f,00,70,00,23,00,33,00,00,00