Monitor Background Image Lost Due to Windows Upgrade

[Roy Dennis]

OK I think you must be referring to Windows background picture or wall paper ?
If so this is not set in Hoster but in Windows.

If your running Windows 10 right click on background on main monitor and select Personalise/Background, either choose a picture from selection shown or if you can’t see your picture browse folders and add to list.
Now if you have your extended monitor connected you can right click on the picture of your choice and select which monitor you want it to appear on.

Hope this is what you are referring to.

Or was it something you originally set using Display fusion software ?