HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\HideDesktopIcons\NewStartPanel\
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\HideDesktopIcons\ClassicStartMenu\
Inside, Make new DWORD-Value with the name "{645FF040-5081-101B-9F08-00AA002F954E}" & 'Modify' Value "1"
To restore the desktop icon again, just 'Modify' the same DWORD-Value to "0"