If File Explorer Preview for PDF is not working or displaying correctly and shows ‘INDEX OF…’ under Network folders, here's what you need to do.

Windows Explorer displayed .pdf files as preview thumbnails on Zill Niazi’s old Windows 7 laptop. But on a new laptop, also running Windows 7, it displays them only as icons. Can this be fixed ...

Download Preview Handler Association Editor to enable Windows Explorer preview pane in Windows 11/10. The tool lets you preview EML and other file types files in Windows File Explorer.

Given how limited the preview pane already feels in Windows 10, even adding just two more file types feels like a huge improvement.