Uninstall Pdf-Creator / Pdf Architect 8 and lost thumbail view on pdf files

I have updated PDF-Creator 4-4-0 (including PDF Architect 8). I uninstalled PDF Architect 8 because I don't need it. However, after uninstalling the software, I lost all the thumbnails of the PDf files and it is impossible to find it. If I unistall PDF-Creator, I have the same result.
Can someone help me? Thx