Preview handler not working in Outlook or windows explorer

Hi everyone,

After installing and uninstalling another pdf reader/merger, I can't preview pdf files with Acrobat reader anymore in the preview handler pane in Windows explorer and in MS Outlook that says me : "this file cannot be previewed because there is no previewer installed for it". I went through every forum, tutorial, etc. I could. I checked the option "Enable PDF thumbnail previews in Windows Explorer" in Adobe reader options... Of course, I uninstalled the third party PDF viewer that I had been using and erased manually the data files that had not been cleared while uninstalling. I also launched a repair of Adobe Reader DC, I tried an uninstall and reinstall of Adobe Reader DC. I ran CCLEANER. I verified the registry entries that were mentioned in other troubleshooting suggestions and verified that one entry was not there per another suggestion.
Does someone has a suggestion to keep using Adobe as my previewer ?

Currently I can see (in windows explorer preview pane) only the thumbnail with the Acrobat reader logo in the preview pane as you can see in the attached file !

Thank you very much for your help and your time !