About 2 days or so I upgraded my version of Lubuntu from 11.04 to 11.10. But the problem is that I now don't know how to change my wallpaper.
Google doesn't give me any answers.
Try typing this in a terminal:
You can change the desktop wallpaper from this window.
And uncheck the box "Show menus provided by window managers when desktop is clicked" found under the "Advanced" tab. Then you should be able to right click on the desktop and get the menu to bring up the preferences window that allows you to change the wallpaper anytime.
Right click the Desktop and choose Desktop Preferences from the pop-up menu.
For Lubuntu 11.10:
In the Appearance Tab you can choose the Wallpaper - all wallpaper has to be in .png format
For Lubuntu 12.04 and above:
In the Appearance Tab you can choose the Wallpaper - wallpaper can be in JPEG or PNG format format