Good morning Mr. Drab, thank you for helping me with this. Notably, I had made an error in downloading the SFCFix.zip file, somehow turning it into a HTML file instead of the proper .zip. (Although SFCFix.exe did execute the script, the result was apparently misleading). I followed the directions, (this time correctly, I hope) and am posting the files requested attached to this reply. The result from the SFC.txt appears markedly different from the first one, now reporting some ownerships and permissions actions. I'm guessing there was a corrupt version of the OpenCL.dll file somewhere that needed to be replaced, and somehow the .zip or the .exe files contained a known good copy. In any case, the SFC /Scannow results were "clean" in the sense that no corruptions detected or fixes applied. That seems like progress to me; perhaps conclusive in so far as this problem is concerned, but you will be able to determine if that's correct or not.