Thanks but that MS Update was from April 2013 and definitely not the issue. I have been running perfectly right up until this first-time-Avast-installation made recently, almost 6 months after the MS Update was released. I always install MS updates within a week after release date… so there is no chance this Update, if even on my system, was installed after May 2013.

Why do you believe an MS Update is the cause for the issue, and why, if it was installed in April, did it wait until I installed Avast in Aug/Sep to begin causing issues? Are you sure my sick drive (SSD) has this KB2823324 Update?