Zum Beispiel:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Photo Viewer\Capabilities\FileAssociations]
".tif"="PhotoViewer.FileAssoc.Tiff"
".tiff"="PhotoViewer.FileAssoc.Tiff"
".jpg"="PhotoViewer.FileAssoc.Tiff"
".png"="PhotoViewer.FileAssoc.Tiff"