New to Avast and I have an issue

Hello everyone, I am new to Avast and I like how it works

But I ran in to a problem with the free version 2014.9.0.2013. I had the free version loaded on two systems and I have two problems.
Problem A
Computer A - trying to do Microsoft updates, got an error 8024402C
Computer B - trying to do Microsoft updates and not problems.

What I did is I turned off all the Avast Shield settings on Computer A and then I was able to update all the ones I needed to do from Microsoft. I went and compared my settings from Computer A against computer B and they look all the same. So I am scratching my head on this

Problem B
Computer A does not have the program that Computer B does. On Computer B the program goes to the Internet and verifies my license, but now it cannot verify it. So on Computer B I turned off the Avast Shield settings and reran the program and now my program gets verified. If I turn the Avast Shields on, Avast blocks it.

So on both instances I am not sure why Avast (or how) is blocking those two issues which are different from each other. Why Avast blocks Microsoft update on Computer A and not on B? Maybe I missed a setting, but not sure. Can anyone help me out on this?

Running Windows 7 64-bit on both systems, both systems have all the Microsoft updates, installed Avast free and I am using the default settings. Just not sure, thanks

did you remove previous used AV and run vendors removal tool before installing avast?
General: Uninstalling a third-party antivirus software http://www.avast.com/en-eu/faq.php?article=AVKB11#artTitle

Try a repair…Control Panel>uninstall a program>double click “avast”>click “repair”>reboot