Yes, no files will open, wherever they are.

- Clipboard-1.jpg (319.38 KiB) Viewed 67 times
Also, the browser will not generate new thumbnails on XP. It displays existing ones, but any new ones appear and then immediately vanish again.
I didn't mention the first time, but the installer doesn't seem to work on XP now either, saying it's not a valid Win32 application.
I installed it using Windows 10, where it shares the same program files folder as XP. Maybe this caused the issue, but see below!
The installer problem is not unusual now, I've run across quite a few programs which will not now install on XP, but work fine if the portable version is used. I guess the installer is not compiled with an XP compatible compiler (or something!)
Unfortunately, the portable version of the current XnView doesn't work on XP either. I extracted it into a different folder on a different drive to the normal installation, and it still won't open any files on XP.
Cheers, Dave.
