Default file associations

I have, for example, .jpg set to open in Photoshop. If I open a jpg file from a Windows Explorer lisitng, it opens in Photoshop, but from Directory Opus it opens in Viewer, no matter how many times I right click the file and select Photoshop as the default program.

How do I sort this out please.

Open the prefs and search for "use internal", the options shown possibly help out.

Thanks for your very quick reply, which has done the trick.