At the time I had a problem with KB3000850, it was my Avast! a/v screwing me over. I was under the impression that Avast! had fixed the issue. I don't know. I dumped them and switched to Panda Free. If you are using Avast, try another a/v.
I am not using any anti-virus software at all. So that is not the problem I am sorry, what is IR4 where you are talking about?