I would visit the Windows Update web site, (Start > All Programs > Windows Update at the top), let Microsoft scan your system and check for updates, then select this update to hide it.
It shouldn't attempt to download again.
I have been getting a security update for months on "Microsoft Virtual Machine". The only problem is I've never had VM. If I go ahead & click O.K it tries to download it,and comes back saying that it wasn't successful,because I didn't really have it to update. But I still can't get it to stop coming on (lower right)screen every time I turn the computer on. There's a yellow symbol down in lower right corner ALL OF THE TIME. Any ideas?