The Internet Explorer namespace icon is hidden from the Desktop by default in Windows Vista. This article tells you how to restore the missing Internet Explorer icon to the Desktop. Note that the desktop icon appears by default when you switch to Classic Start menu.
HKEY_CURRENT_USER \ Software \ Microsoft \ Windows \ CurrentVersion \ Explorer \ HideDesktopIcons \ NewStartPanel
Note: If the above branch does not exist, you need to create the keys manually.