I've set image files to open with irfanview. However, whenever I double click an image file it opens in the default dopus image viewer.
What am I doing wrong?
You can find that setting under -> settings -> preferences -> file operations -> doubleclick -> "use internal viewer for".If you untick the checkbox, it should open in Irfanview.
If you need more info about using or not using the Opus viewer inside and outside of Opus, the first two FAQs in the section shown below have it: