How to remove PDF Architect 8 Preview Handler

I have been using ver 7 for a year but had limited functionality. In April I tried ver 8 but still was asked to pay extra for additional functionality so I decided to remove it from my Windows 10 pc. I did all I could, de0installed, removed all files and folders aaand switched to Adobe PDF reader. All happy BUT ...
I canit view pdf files in the Windows file explorers views.
WIndows tells me that:
This file cant be previewed because of an error in PDF Architect 8 Preview Handler.

Could you please let me know how can I remove this error and allow Acrobat to do the previews for my PDF files.
Adobe Acrobat Reader has tick for Enable PDF thumbnail previews in WIndow Explorer.
I am able to amend REGISTRY files if needed but will need clear instructions and paths to find the correct files to change or remove

Your help willbe awaited and appreciated