If you are trying to update at the Microsoft website, make sure you haven't set Kerio to block ActiveX- you will need it for the update process. (double click the Kerio icon and select Web>Ad Blocking. Make sure the Block ActiveX box is unchecked.)
Appart from that, as David said, we really need more information in order to help you. I use Kerio and avast! and can update with no problem, so we should be ableto find a solution to this one.