OK thanks for the quick response!

I guess that will be a topic for another day! :)

Thanks for that explanation Shawn. Just wanted to clarify a couple of things:

#1 - both methods (.bat file method & clear history in explorer method) accomplish exactly the same things, and one...

I think the problem may be that your pdf file associations have been disrupted. I went through this problem before with windows 10, where it would not show the pdf thumb image in windows explorer,...