|Here's an update for others who may be experiencing similar woes:|
After chasing this thing for days/weeks...finally out of desperation, turned to Comcast Online Malware Removal support - not cheap - $130US, but ultimately worth every penny, as I learned the process to be able to do this to my own system:
1. The Tech logged on to my computer remotely which I was able to monitor every keystroke and ask detailed questions which he patiently answered.
2. Did many tests etc. cleaned up registry, services startup etc.
3. Finally upon running a battery of test software, most of which is available like Malwarebytes(first prog he installed and ran)Process Explorer and Autoruns from sysintervals.com, the Tech installed remotely, TDSS Killer scan by Kaspersky (free tool downloadable) a rootkit malware was found (Rootkit.win32.TDSS.tdl4)
4. TDSS then prompted to cure. Problem resolved....so far...no further file I/O creashes etc.
To the staff at Malwarebytes, thanks for all your help.