XnView Software

So perhaps the 'Only one instance' option Almost........when I use this option a tab which is already open gets replaced by another picture (tab) which I open from outside Xnview (Windows explorer). But you've put me on the right track!! Disabling the option via Tools --> Options --> View --> "Open...

I've been searching for an hour in this forum for the answer on how to get Xnview to work in a single window mode . If the answer to my question is still already out there, I apologize! No matter what I open after Xnview is already opened, I want it to open in the existing Xnview window in another t...