You can change various "special" folders here:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders\Desktop
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders\Desktop
in the attached pic you can see I've relocated my "Desktop" to my E: drive which helps me save time when I have to re-image the boot-drive.