Removes the icon overlay from the taskbar button.
Returns one of the following values.
S_OK The operation completed successfully. E_ACCESSDENIED The current page is not a pinned site. E_NOTIMPL This method is not supported on Windows CE.
This method clears an icon overlay that was previously set with the msSiteModeSetIconOverlay method. Icon overlays communicate alerts, notifications, and application status to users.
Each pinned site button on the taskbar can declare one icon overlay. If the taskbar button represents a group of windows, the icon overlay might be replaced by another in the group when it is removed.