Subject line says it all. I'd like to enable the DOpus Standalone Viewer to replace the default Windows Photo Viewer. After searching the forum, I've CHECKED (to enable) the setting in Preferences/File Operations/Double-click on Files/Use internal picture viewer for [all recognized pictures] but still no joy. I've tried un-checking it, checking it again, etc. numerous times. I also looked at Viewer Plugins and see Universal Graphics Viewer listed there, but when I click on a .jpg it still opens in WPV. Thanks in advance for any help folks, I appreciate it. DP
Are you double-clicking the JPG inside of Opus, or outside of Opus?
I recommend disabling the Universal Graphics Viewer plugin, until you get things working, in case it is involved somehow.
Doh! You ask good questions 
) It worked when I clicked inside Opus. Then for outside Opus, I set the file-type (.jpg) to open with d8viewer.exe and that works now too. Thanks a lot Leo. I appreciate your help.