I made an account just to thank you for this answer! This is the solution that I was looking for. I assume you mean to un-check the "Check for program updates..." setting. This post is the Best Answer/Solution in my opinion.
On a side note, all of these comments about MB definitions needing to be updated to protect you from zero-days is BOGUS. Nothing that uses definitions to check for malware can reliably stop a true zero-day attack, because a zero-day is something that by definition has not been seen before! A heuristic scan would have a better chance of detecting something like that, but heuristic detection shouldn't need updated malware signatures to operate, so the people who keep saying that updating definitions will protect you against zero-days seem to just be spreading misinformation.
