Have you tried the workaround offered here?
Error message when you try to install updates by using the Windows Update
Web site: "0x80245003"
http://support.microsoft.com/kb/919749/EN-US/
"0609" <> wrote in message
news:92A9B044-83B6-4C12-B836-...
> How do i solve it..? I am unable to update my windows defender. The
> solution
> doesn't seem to be on the support page and there are queries about this
> error
> that are unanswered. Pls help.